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HlPPARCHUS IN THE OBSERVATORY OF ALEXANDRIA. 



THE STORY 



OF THE 



SUN, MOON, AND STARS 



BY 



AGNES GIBERNE 

Author of "The Starry Skies," "The World's Foundations, 
"Radiant Suns," Etc. 



WITH COPIOUS ADDITIONS 



FuTIg -ttluslrHieri 



CINCINNATI 

NATIONAL BOOK COMPANY 






-A 






23124 



COPYRIGHT, 1898, 
BY J. T. JONES. 

TWO COPIES REC i.VED. 







INTRODUCTION. 



By Charges Pritchard, M. A., F. R. S., 

Professor of Astronomy in the University of Oxford. 



The pages of this volume on a great subject were 
submitted to my criticism while passing through the 
press, with a request from a friend that I would make 
any suggestions which might occur to me for its im- 
provement. Naturally, such a request was entertained, 
in the first instance, with hesitation and misgiving. 
But after a rapid perusal of the first sheet, I found my 
interest awakened, and then gradually secured ; for the 
book seemed to me to possess certain features of no 
ordinary character, and, in my judgment, held out the 
promise of supplying an undoubted want, thus en- 
abling me to answer a question which I have been 
often asked, and which had as often puzzled me, to 
the effect, " Can you tell me of any book on astron- 
omy suited to beginners ?" I think just such a book 
is here presented to the reader; for the tale of the 
stellar universe is therein told with great simplicity, 
and perhaps with sufficient completeness, in an ear- 
nest and pleasant style, equally free, I think, from in- 

5 



/" 



6 INTRODUCTION. 

accuracy or unpardonable exaggeration. We have 
here the outlines of elementary astronomy, not merely 
detailed without mathematics, but to a very great ex- 
tent expressed in untechnical language. Success in 
such an attempt I regard as a considerable feat, and 
one of much practical utility. 

For the science of astronomy is essentially a science 
of great magnitude and great difficulty. From the 
time of Hipparchus, some century and a half before 
the Christian era, down to the present day, the culti- 
vation of astronomy has severely taxed the minds of a 
succession of men endowed with the rarest genius. 
The facts and the truths of the science thus secured 
have been of very slow accretion ; but like all other 
truths, when once secured and thoroughly understood, 
they are found to admit of very simple verbal expres- 
sion, and to lie well within the general comprehension, 
and, I may safely add, within the sympathies of all 
educated men and women. 

Thus the great astronomers, the original discover- 
ers of the last twenty centuries, have labored, each in 
his separate field of the vast universe of nature, and 
other men, endowed with other gifts, have entered on 
their labors, and by systematizing, correlating, and 
simplifying the expression of their results, have 
brought the whole within the grasp of cultivated 
men engaged in other branches of the varied pursuits 
of our complicated life. It is in this sort of order 



INTRODUCTION. 7 

that the amelioration and civilization of mankind 
have proceeded, and at the present moment are, I 
hope and believe, rapidly proceeding. 

It was, I suspect, under this point of view, though 
half unconsciously so, that my attention was arrested 
by the book now presented to the reader; for we 
have here many of the chief results of the laborious 
researches of such men as Ptolemy, Kepler, Newton, 
Herschel, Fraunhofer, Janssen, Lockyer, Schiapa- 
relli, and others — no matter where accumulated or by 
whom recorded — filtered through the mind of a 
thoughtful and cultured lady, and here presented to 
other minds in the very forms wherein they have been 
assimilated and pictured in her own. And these forms 
and pictures are true. It is in this way that the intel- 
lectual "protoplasm" of the human mind is fostered 
and practically disseminated. 

And, then, there is still another point of view from 
which this general dissemination of great truths in a 
simple style assumes an aspect of practical impor- 
tance. I allude to the influences of this process on 
the imaginative or poetic side of our complex nature. 

Wordsworth, in one of his prefaces, has stated so 
clearly the truth on this subject that I can not do bet- 
ter than give his words. "If the time should ever 
come," he says, "when what is now science becomes 
familiarized to men, then the remotest discoveries of 
the chemist, the botanist, the mineralogist, will be as 



8 INTRODUCTION. 

proper objects of the poet's art as any upon which it 
can be employed. He will be ready to follow the 
steps of the man of science; he will be at his side, 
carrying sensation into the midst of the objects of 
science itself. The poet will lend his divine spirit to 
aid the transfiguration, and will welcome the being 
thus produced as a dear and genuine inmate of the 
household of man." 

It is for reasons such as here stated that I heartily 
commend this book to the attention of those who 
take an interest in the advancement of the intel- 
lectual progress and culture of society. The story of 
the Kosmos is told by the authoress in her own lan- 
guage and after her own method. I believe, as I have 

said, the story is correct. 
Oxford University. 



CONTENTS 



Chapter. Page. 

I. The Earth One of a Family, 13 

II. The Head of Our Family, 24 

III. What Binds the Family Together, ....... 34 

IV. The Leading Members of Our Family. — First 

Group, . 46 

V. The Leading Members of Our Family. — Second 

Group, 55 

VI. The Moon, 62 

VII. Visitors, 73 

VIII. Little Servants, = 83 

IX. Neighboring Families, .95 

X. Our Neighbors' Movements, . . 106 

XL More About the Solar System, 122 

XII. More About the Sun, .133 

XIII. Yet Morf About the Sun, 148 

XIV. More About the Moon, 157 

XV. Yet More About the Moon, 164 

XVI. Mercury, Venus, and Mars, , . 180 

XVII. Jupiter, . 199 

XVIII. Saturn, 214 

XIX. Uranus and Neptune, 225 

XX. Comets and Meteorites, 240 

XXI. More About Comets and Meteorites, 246 

XXII. Many Suns, 267 

9 



IO CONTENTS. 

Chapter. Page. 

XXIII. Some Particular Suns, . . . . , . 278 

XXIV. Different Kinds of Suns 291 

XXV. Groups and Clusters of Suns, 304 

XXVI. The Problem of Sun and Star Distances, . . .310 

XXVII. Measurement of Star Distances, 320 

XXVIII. The Milky Way, 329 

XXIX. A Whirling Universe, 337 

XXX. Reading the Light, 344 

XXXI. Stellar Photography 355 

XXXII. The Dawn of Astronomy, 363 

XXXIII. Modern Astronomy, 375 

XXXIV. Sir Isaac Newton, 382 

XXXV. Later Astronomy, 393 



LIST OF ILLUSTRATIONS. 



Page. 

Hipparchus in the Observatory at Alexandria Frontispiece. 

The Solar System 15 

The Pleiades 19 

Sun-spots 29 

Phases of Mercury before Inferior Conjunction — Evening Star 50 

Appearance of the Full Moon 63 

One Form of I,unar Crater 69 

The Earth as Seen from the Moon 71 

Passage of the Earth and the Moon through the Tail of a Comet 76 

Passage of the Comet of 1843 Close to the Sun 79 

Meteor Emerging from Behind a Cloud 84 

The Great Shower of Shooting-stars, November 27, 1872 90 

Constellation of the Great Bear 108 

The Great Bear 50,000 Years Ago 109 

The Great Bear 50,000 Years Hence 109 

Constellation of Orion as it Appears Now no 

Constellation of Orion 50,000 Years Hence in 

Position of Planets Inferior to Jupiter — Showing the Zone of the 

Asteroids 123 

Comparative Size of the Planetary Worlds 130 

A Typical Sun-spot 135 

A Solar Eruption 138 

Sun-flames, May 3, 1892 143 

Solar Corona and Prominence 152 

Comparative Size of the Earth and Sun 155 

The Moon— an Expired Planet 159 

The L,unar Crater Copernicus 170 

I,unar Eruption— Brisk Action 172 

Lunar Eruption — Feeble Action 173 

Nicolaus Copernicus : 176 

Phases of Venus 186 

11 



12 LIST OF ILLUSTRATIONS,. 

Page. 

Mars and the Path of its Satellites 191 

General Aspect of Jupiter — Satellite and its Shadow 200 

Satellites of Jupiter Compared with the Earth and Moon 206 

The System of Jupiter 208 

Orbits of Nine Comets Captured by Jupiter 213 

Saturn and the Earth — Comparative Size 215 

Ideal View of Saturn's Rings and Satellites from the Planet 222 

Great Astronomers of Earlier Times , 227 

The Great Comet of 1811 247 

Donates Comet, 1858 249 

Great Comet of 1744 254 

The First Comet of 1888— June 4 255 

Great Comet of 1680 260 

Great Comet of 1769 261 

Baron Alexander Von Humboldt 264 

A Telescopic Field in the Milky Way 270 

Cygnus, Constellation of 279 

Stars whose Distances are Best Known 281 

Lyra, Constellation of 297 

Constellations in the Northern Hemisphere 300 

A Cluster of Stars in Centaurus 305 

The Great Nebula in Andromeda, Compared with Size of the Solar 

System 307 

A Cluster of Stars in Perseus 332 

Hercules, Constellation of 338 

The Great Bear, Constellation of 341 

The Prism and Spectrum. . : 344 

The Spectrocope 345 

Spectra, Showing the Dark Lines 347 

Great Astronomers of Later Times 377 

Eye-piece of Lick Telescope 407 

Lick Observatory 409 

Professor E. E. Barnard 410 



THE STORY 



of thk 



SUN, MOON, AND STARS. 



CHAPTER I 



THE EARTH ONE OF A FAMILY. 

What is this earth, of ours? 

Something very great — and yet something very 
little. Something very great, compared with the 
things npon the earth ; something very little, com- 
pared with the things outside the earth. 

And as our journey ings together are for a while to 
be away from earth, we shall find ourselves obliged 
to count her as something quite small in the great 
universe, where so many larger and mightier things 
are to be found, — if indeed they are mightier. Not 
that we have to say good-bye altogether to our old 
home. We must linger about her for a while before 
starting, and afterwards it will be often needful to 
come back, with speed swifter than the flight of light, 
that we may compare notes on the sizes and condi- 
tions of other places visited by us. 

But first of all: what is this earth of ours? 

It was rather a pleasant notion which men held in 
olden days, that we — that great and important "We" 

13 



14 STORY OF THE SUN, MOON, AND STARS. 

which loves to perch itself upon a height — stood firm 
and fixed at the very center of everything. The earth 
was supposed to be a vast flat plain, reaching nobody 
could tell how far. The sun rose and set for us alone ; 
and the thousands of stars twinkled in the sky at night 
for nobody's good except ours ; and the blue sky over- 
head was a crystal covering for the men of our earth, 
and nothing more. In fact, people seem to have 
counted themselves not merely to have had a kind of 
kingship over the lower animals of our earth, but to 
have been kings over the whole universe. Sun, stars, 
and sky, as well as earth, were made for man, and for 
man only. 

This was the common belief, though even in those 
olden days there were some who knew better. But the 
world in general knows better now. 

Earth the center of the universe ! Why, she is not 
that of even the particular family in the heavens to 
which she belongs. For we do not stand alone. The 
earth is one of a family of worlds, and that family is 
called The Solar System. And so far is our earth 
from being the head of the family, that she is not 
even one of the more important members. She is 
merely one of the little sisters, as it were. 

Men not only believed the earth, in past days, to 
be at the center of the universe ; but also they believed 
her to remain there without change. Sun, moon, stars, 
planets, sky, might move ; but never the earth. The 
solid ground beneath their feet, that at least was firm. 
Every day the sun rose and set, and every night the 
stars, in like manner, rose and set. But this was 
easily explained. We on our great earth stood firm 



THE EARTH ONE OF A FAMILY. 



15 



and still, while sun, moon, stars, went circling round 
us once in every twenty-four hours, just for our sole 




THE SOI,AR SYSTEM. 



and particular convenience. What an important per- 
sonage man must have felt himself then in God's great 
universe ! Once again, we know better now ! 



1 6 STORY OF THK SUN, MOON, AND STARS. 

For it is the earth that moves, and not the sun; it 
is the earth that moves, and not the stars. The daily 
movements of sun and stars, rising in the east, travel- 
ing over the sky, and setting in the west, are no more 
real movements on their part than, when we travel in 
a railway-train, the seeming rush of hedges, telegraph 
posts, houses, and fields is real. They are fixed and 
we are moving ; yet the movement appears to us to be 
not ours but theirs. 

Still more strongly would this appear to be the case 
if there were no noise, no shaking, no jarring and 
trembling, to make us feel that we are not at rest. 
Sometimes when a train begins to move gently out of 
a station, from among other trains, it is at the first 
moment quite impossible to say whether the move- 
ment belongs to the train in which we are seated or to 
a neighboring train. And in the motions of our earth 
there is no noise, no shaking, no jarring — all are rapid, 
silent, and even. 

If you were rising through the air in a balloon, you 
would at first only know your own movement by see- 
ing the earth seem to drop away from beneath you. 
And just so we can only know the earth's movements 
by seeing how worlds around us seem to move in con- 
sequence. 

When I speak of the Universe, I mean the whole of 
God's mighty creation as far as the stars reach. Some- 
times the word is used in this sense, and sometimes 
it is used only for a particular part of creation nearer 
to us than other parts. At present, however, we will 
put aside all thought of the second narrower meaning. 

The wisest astronomer living can not tell us how 



THE EARTH ONE OF A FAMILY. 1 7 

far the stars reach. We know now that there is no 
firm crystal covering over onr heads, dotted with 
bright points here and there ; bnt only the wide open 
sky or heaven, containing millions of stars, some 
nearer, some farther, some bright enough to be seen 
by us all, some only visible through a telescope. 

People talk often of the stars being "set in space;" 
and the meaning of " space " is simply "room." Where 
you are must be space, or you could not be there. 
But it is when we get away from earth, and travel in 
thought through the wide fields of space, where God 
has placed his stars, that we begin to feel how vast it 
is, and what specks we are ourselves— nay, what a 
speck our very earth is, in this great and boundless 
creation. 

For there is no getting to the borders of space. 
As one telescope after another is made, each one 
stronger in power and able to reach farther than the 
last, still more and more stars are seen, and yet more 
and more behind and beyond, in countless millions. 

It is the same all round the earth. The old notion 
about our world being a fiat plain has been long since 
given up. We know her now to be a round globe, 
not fixed, but floating like the stars in space. 

When you look up into the sky, you are look- 
ing exactly in the opposite direction from where 
you would be looking up if you were in Australia. 
For Australia's "up" is our "down," and our "down" 
is Australia's "up." Or, to put it more truly, "up" is 
always in the direction straight away from this earth, 
on whatever part of it you may be standing; and 
"down " is always towards the center of the earth. 



l8 STORY OF THE SUN, MOON, AND STARS. 

All round the globe, in north, south, east, west, 
whether you are in Europe, Asia, Africa, or America, 
though you will see different stars in certain different 
quarters of the earth, still overhead you will find shin- 
ing countless points of light. , . 

And now, what are these stars ? This is a matter 
on which people are often confused, and on which 
it is well to be quite clear beforegoing one step 
farther. 

Some of the stars you have most likely often no- 
ticed. The seven chief stars of the Great Bear are 
known to a large number of people ; and there are few 
who have not admired the splendid constellation ot 
Orion. Perhaps you also know the W-shape of Cas- 
siopeia, and the brilliant shining of Sirius, and the 
soft glimmer of the Pleiades. 

The different constellations or groups of principal 
stars have been watched by men for long ages past. 
They are called the fixed stars, for they do not change. 
How many thousands of years ago they were first ar- 
ranged by men into these groups, and who first gave 
them their names, we can not tell. 

True, night by night, through century after cen- 
tury, they rise, and cross the sky, and set. But those 
are only seeming movements. Precisely as the turn- 
ing round of the earth upon her axis, once in every 
twenty-four hours, makes the sun appear to rise and 
cross the sky and set, in the day-time ; so also the 
same turning of the earth makes the stars appear to 
do the same in the night-time. 

There is another seeming movement among the 
stars, which is only in seeming. Some come into 



THE EARTH ONE OF A FAMILY. 



19 



view in summer which can not be seen in winter ; and 
some come into view in winter which can not be seen 
in summer. For the sun, moving on his pathway 
through the sky, hides those stars which shine with 
him in the day-time. The zodiac is an imaginary 
belt in the heavens, sixteen or eighteen degrees wide, 
containing the twelve constellations through which 
the sun passes. And as he passes from point to point 
of his pathway, he constantly conceals from us fresh 
groups of stars by day, and allows fresh groups to ap- 
pear by night. 
Speaking gen- 
erally, however, 
the stars remain 
the same year 
after year, cen- 
tury after centu- 
ry. The groups 
may still be seen 
as of old, fixed 
and unchanging. THE p^iades. 

What are these stars? Stars and planets have 
both been spoken about. There is a great difference 
between the two. 

Perhaps if you were asked whether the sun is most 
like to a star or a planet, you would be rather at a loss ; 
and many who have admired the brilliant evening 
star, Venus, often to be seen after sunset, would be 
surprised to learn that the evening star is in reality no 
star at all. 

A star is a sun. Our sun is nothing more nor less 
than a star. Each one of the so-called " fixed stars," 




20 STORY OK THE SUN, MOON, AND STARS. 

that you see shining at night in the sky, is a sun like 
our sun; only some of the stars are larger suns and 
some are smaller suns than ours. 

The main reason why our sun looks so much larger 
and brighter than the stars is, that he is so very much 
nearer to us. The stars are one and all at enormous 
distances from the earth. By and by we will go more 
closely into the matter of their distance, compared 
with the distance of the sun. 

At present it is enough to say that if many of the 
stars were placed just as near to us as our sun is 
placed, they would look just as large and bright; 
while there are some that would look a great deal 
larger and brighter. And if our sun were to travel 
away from us, to the distance of the very nearest 
of the little twinkling stars, he would dwindle down 
and down in size and brilliancy, till at last we should 
not be able to tell him apart from the rest of the 
stars. 

I have told you that the stars are called " fixed " 
because they keep their places, and do not change from 
age to age. Though the movement of the earth makes 
them seem all to sweep past every night in company, 
yet they do not travel in and out among one another, 
or backwards and forwards, or from side to side. At 
all events, if there be such changes, they are so slow 
and so small as to be exceedingly difficult to find out. 
Each group of stars keeps its own old shape, as for 
hundreds of years back. 

But among these fixed stars there are certain stars 
which do go to and fro, and backwards and forwards. 
Now they are to be seen in the middle of one constel- 



THE EARTH ONE OF A FAMILY. 21 

lation, and now in the middle of another. These rest- 
less stars were long a great perplexity. Men named 
them Planets or Wanderers. 

We know now that the planets are in reality not 
stars at all, and also that they are not nearly so far 
away from us as the fixed stars. In fact, they are 
simply members of our own family — the Solar System. 
They are worlds, more or less like the world we live 
in; and they travel round and round the sun as we 
do, each more or less near to him; and they depend 
upon him for heat and light, in more or less the same 
manner as ourselves. 

Therefore, just as our sun is a star, and stars are 
suns, so our earth or world is a planet, and planets 
are worlds. Earth is the name we give to that par- 
ticular world or planet on which we live. Planets 
may generally be known from stars by the fact that 
they do not twinkle. But the great difference be- 
tween the two lies in the fact that a star shines by 
its own radiant, burning light, whereas a planet shines 
merely by light reflected or borrowed from the sun. 

But how were the earth and the other worlds made? 
Let us imagine an immense gaseous mass placed in 
space. Attraction is a force inherent in every atom of 
matter. The denser portion of this mass will insen- 
sibly attract towards it the other parts, and in the slow 
fall of the more distant molecules towards this more 
attractive region, a general motion is produced, in- 
completely directed towards this center, and soon in- 
volving the whole mass in the same motion of rota- 
tion. The simplest form of all, even in virtue of this 
law of attraction, is the spherical form. It is that 



22 STORY OF THE SUN, MOON, AND STARS. 

which a drop of water takes, and a drop of mercury 
if left to itself. 

The laws of mechanics show that, as this gaseous 
mass condenses and shrinks, the motion of rotation of 
the nebula is accelerated. In turning, it becomes 
flattened at the poles, and gradually takes the form of 
an immense lens-shaped mass of gas. It has begun 
to turn so quickly as to develop at its exterior cir- 
cumference a centrifugal force superior to the general 
attraction of the mass, as when we whirl a sling. The 
inevitable consequence of this excess is a rupture of 
the equilibrium, which detaches an external ring. 
This gaseous ring will continue to rotate in the same 
time and with the same velocity; but the nebulous 
mother will be henceforth detached, and will continue 
to undergo progressive condensation and acceleration 
of motion. The same feat will be reproduced as often 
as the velocity of rotation surpasses that by which the 
centrifugal force remains inferior to the attraction. It 
may have happened also that secondary centers of 
condensation would be formed even in the interior of 
the nebula. 

In our system the rings of Saturn still subsist. 

The successive formation of the planets, their sit- 
uation near the plane of the solar equator, and their 
motions of translation round the same center, are ex- 
plained by the theory which we are discussing. The 
most distant known planet, Neptune, would be de- 
tached from the nebula at the epoch when this nebula 
extended as far as the planet, out to nearly three thou- 
sand millions of miles, and would turn in a slow revo- 
lution requiring a period of 165 years for its accom- 



THE EARTH ONE OF A FAMILY. 23 

plishment. The original ring could not remain in the 
state of a ring unless it was perfectly homogeneous 
and regular ; but such a condition is, so to say, unre- 
alizable, and it did not delay in condensing itself into 
a sphere. Successively, Uranus, Saturn, Jupiter, the 
army of small planets, Mars, would thus be detached 
or formed in the interior of this same nebula. After- 
wards came the earth, of which the birth goes back 
to the epoch when the sun had arrived at the earth's 
present position. Venus and Mercury would be born 
later. Will the sun give birth to a new world? This 
is not probable. 



CHAPTER II. 

THE HEAD OF OUR FAMILY. 

PKOPLK began very early in trie history ot the 
world to pay close attention to the^ snn. And no 
wonder. We owe so much to his heat and light that 
the marvel would be if men had not thought much 
about him. 

Was the sun really any larger than he looked, and 
if so, how much larger was he? And what was his 
distance from the earth? These were two of the ques- 
tions which puzzled our ancestors the longest. If 
once they could have settled exactly how far off the 
sun really was, they could easily have calculated his 
exact size; but this was just what they could not do. 

So one man supposed that the sun must be quite 
near, and very little larger than he looked. Another 
thought he might be seventy-five miles in diameter. 
A third ventured to believe that he was larger than 
the country of Greece. A fourth was so bold as to 
imagine that he might even outweigh the earth 
herself. 

After a while many attempts were made to measure 
the distance of the sun; and a great many different 
answers to this difficult question were given by differ- 
ent men, most of them very wide of the mark. It is 
only of late years that the matter has been clearly 
settled. And, indeed, it was found quite lately that a 
mistake of no less than three millions of miles had 

24 



THE HEAD OF OUR FAMILY. 25 

been made, notwithstanding all the care and all the 
attention given. But though three millions of miles 
sounds a great deal, yet it is really very little — only a 
tiny portion of the whole. 

For the distance of the sun from the earth is no 
less than about ninety-three millions of miles. 
Ninety-three millions of miles ! Can you picture that 
to yourself? Try to think what is meant by a thou- 
sand miles. Our earth is eight thousand miles in 
diameter. In other words, if you were to thrust a 
gigantic knitting-needle through her body, from the 
North Pole to the South Pole, it would have to be 
about eight thousand miles long. 

To reach the thought of one million, you must pic- 
ture one thousand times one thousand. Our earth is 
about twenty-five thousand miles round. It you were 
to start from the mouth of the River Amazon, in South 
America, and journey straight round the whole earth on 
the equator, till you came back to the same point, you 
would have traveled about twenty-five thousand miles. 
But that would be a long way off from a million miles. 
You would have gone only once round the earth. 
Now a cord one million miles in length could be 
wrapped, not once only, but forty ttmes y round and 
round the earth. And when you have managed to 
reach up to the thought of one million miles, you have 
then to remember that the sun's distance is ninety- 
three times as much again. So, to picture clearly to 
ourselves the actual meaning of " ninety- three mil- 
lions of miles' ' is not so easy. 

Suppose it were possible to lay a railroad from here 
to the sun. If you could journey thither in a per- 



26 STORY OF THE SUN, MOON, AND STARS. 

fectly straight line, at the rate of thirty miles an hour, 
never pausing for one single minute, night or day, you 
would reach the sun in about three hundred and forty- 
six years. 

Thirty miles an hour is a slow train. Suppose we 
double the speed, and make it an express train, rush- 
ing along at the pace of sixty miles an hour. Then 
you might hope to reach the end of your journey in 
one hundred and seventy-three years. If you had 
quitted this earth early in the eighteenth century, 
never stopping on your way, you would be, just about 
now, near the end of the nineteenth, arriving at the sun. 

So much for the sun's distance from us. Now as 
to his size. 

I have already mentioned that our earth's diameter 
— that is, her through measure, as, for instance, the 
line drawn straight from England through her center 
to New Zealand — is about eight thousand miles. This 
sounds a good deal. But what do you think of the 
diameter of the sun being no less than eight hundred 
and fifty -eight thousand miles f The one is eight thou- 
sand miles, the other over eight hundred thousand ! 

Suppose you had a long slender pole which would 
pass through the middle of the earth, one end just 
showing at the North Pole and the other at the South 
Pole. You would need more than a hundred and 
eight of such poles, all joined together, to show the 
diameter of the sun. 

The sun seems not to be made of nearly such heavy 
materials as the earth. He is what astronomers call 
less " dense," less close and compact in his make, just 
as wood is less dense and heavy than iron. Still, his 



THE HKAD OF OUR FAMILY. 27 

size is so enormous, that if you could have a pair of 
gigantic scales, and put the sun into one scale and 
the earth with every one of her brother and sister 
planets into the other, the sun's side would go down 
like lightning. He would be found to weigh seven 
hundred and fifty times as much as all the rest put 
together. And, it would take more than twelve hun- 
dred thousand little earths like ours, rolled into one 
huge ball, to make a globe as large as the sun. 

In the beginning of the seventeenth century a man 
named Fabricius was startled by the sight of a certain 
black spot upon the face of the sun. He watched till 
too dazzled to look any longer, supposing it to be a 
small cloud, yet anxious to learn more. Next day 
the spot was there still, but it seemed to have moved 
on a little way. Morning after morning this move- 
ment was found to continue, and soon a second spot, and 
then a third spot, were observed creeping in like man- 
ner across the sun. After a while they vanished, one 
at a time, round his edge, as it were ; but after some 
days of patient waiting on the part of the lookers-on, 
they appeared again at the opposite edge, and once 
more began their journey across. 

Fabricius seems to have been the first, but he was 
not the last, to watch sun-spots. Many astronomers 
have given close attention to them. Modern tele- 
scopes, and the modern plan of looking at the sun 
through darkened glass, have made this possible in a 
way that was not possible two or three hundred years 
ago. 

The first important discovery made through the 
spots on the sun, was that the sun turns round upon 



28 STORY OF THE SUN, MOON, AND STARS. 

his axis, just in the same manner that the earth turns 
round upon hers. Instead of doing' so once in the 
course of each twenty-four hours, like the earth, he 
turns once in the course of about twenty-five days. 

It must not be supposed that the spots seen now 
upon the sun are the same spots that Fabricius saw 
so long ago. There is perpetual change going on; 
new spots forming, old spots vanishing; one spot break- 
ing into two, two spots joining into one, and so on. 
Even in a single hour great alterations are sometimes 
seen to take place. 

Still, many of the spots do remain long enough and 
keep their shapes closely enough to be watched from 
day to day, and to be known again as old friends when 
they reappear, after being about twelve days hidden 
on the other side of the sun. So that the turning of 
the sun upon his axis has become, after long and care- 
ful examination, a certain known fact. 

For more than thirty years one astronomer kept 
close watch over the spots on every day that it was 
possible to see the sun. Much has been learned from 
his resolute perseverance. 

Now what are these spots ? 

One thing seems pretty sure, and that is that they 
are caused by some kind of tremendous storms or 
cyclones taking place on the surface of that huge ball 
of fire. 

The first attentive observer of the sun, Scheiner, 
at first regarded the spots as satellites— an indefensi- 
ble opinion, which, however, some have attempted to 
revive. Galileo attributed them to clouds or vapors 
floating in the solar atmosphere; this was the best 



THB HEAD OF OUR FAMILY. 



29 



conclusion which could be drawn from the observa- 
tions of that epoch. This opinion met for a long 
time with general approval ; it has even been renewed 
in our day. Some astronomers, and among them 




SUN SPOTS. 



Lalande, believed, on the contrary, that they were 
mountains, of which the flanks, more or less steep, 
might produce the aspect of the penumbra — an opin- 
ion irreconcilable with the proper motion which the 
spots sometimes possess in a very marked manner. 
It is not usual, in fact, to see mountains traveling. 



3o 

Derham attributed them to the smoke issuing from 
the volcanic craters of the sun, an opinion revived and 
maintained in recent times by Chacornac. Several 
savants, regarding the sun as a liquid and incandescent 
mass, have also explained the spots [by immense cin- 
ders floating on this ocean of fire. But a century had 
scarcely elapsed after the epoch when the spots were 
observed for the first time, when an English astron- 
omer, Wilson, showed with certainty that the spots are 
hollow. 

We do not know with any certainty whether the 
sun is through and through one mass of glowing mol- 
ten heat, or whether he may have a solid and even 
cool body within the blazing covering. Some have 
thought the one, and some the other. We only know 
that he is a mighty furnace of heat and flame, beyond 
anything that we can possibly imagine on our quiet 
little earth. 

It seems very sure that no such thing as " quietness " 
is to be found on the surface of the sun. The wildest 
and fiercest turmoil of rushing wind and roaring flame 
there prevails. The cyclones or hurricanes which take 
place are sometimes so rapid and so tremendous in 
extent, tearing open the blazing envelope of the sun, 
and showing glimpses of fiery though darker depths 
below, that we, on our far-distant earth, can actually 
watch their progress. 

Astronomers speak of the " quivering fringe of fire " 
all around the edge of the sun, visible through tele- 
scopes. But the sun is perpetually turning on his 
axis, so that each hour fresh portions of his surface 
thus pass the edge, showing the same appearance. 



THE HEAD OF OUR FAMILY. 3 1 

What conclusion can we come to but that the whole 
enormous surface of the sun is one restless, billowy 
sea of fire and flame? 

It sounds to us both grand and startling to hear of 
the mighty outbreaks from Mount Vesuvius, or to read 
of glowing lava from a volcano in Hawaii pouring in 
one unbroken stream for miles. 

But what shall be thought of rosy flames mounting 
to a height of fifty or a hundred thousand miles above 
the edge of the sun? What shall be thought of a 
tongue of fire long enough to fold three or four times 
round our solid earth? What shall be thought of the 
awful rush of burning gases, sometimes seen, borne 
along at the rate of one or two or even three hundred 
miles in a single second across the sun's surface? 
What shall be thought of the huge dark rents in this 
raging fiery ocean, rents commonly from fifty to one 
hundred thousand miles across, and not seldom more? 

Fifty thousand miles ! A mere speck, scarcely 
visible without a telescope; yet large enough to hold 
seven earths like ours flung in together. The largest 
spot measured was so enormous that eighteen earths 
might have been arranged in a row across the breadth 
of it, like huge boulders of rock in a mountain cavern; 
and to have filled up the entire hole about one hundred 
earths would have been needed. 

It is well to grow familiar with certain names given 
by astronomers to certain parts of the sum 

The round shining disk or flat surface, seen by all 
of us, is called the photosphere, or "light-sphere." It 
has a tolerably well-defined edge or "limb," and daz- 
zles the eye with its intense brightness. 



32 STORY OF THE SUN, MOON, AND STARS. 

Across the photosphere the spots move, sometimes 
many, sometimes few, in number. Besides the dark 
spots, there are spots of extreme brilliancy, standing 
out on even that dazzling surface, which causes a piece 
of white-hot iron to look black and cold by contrast. 
These extra-radiant spots which come and go, and at 
times change with great rapidity, are named faculce — 
a Latin word meaning " torches." 

At the edge of the photosphere astronomers see 
what has been already mentioned, that which is some- 
times called the chromotosphere, which one has named 
"the sierra^ and which another has described as "a 
quivering fringe of fire." The waves of the sea, on a 
stormy day, seen in the distance rising and breaking 
the horizon-line, may serve as an illustration ; only in 
the sun the waves are of fire, not water. What must 
their height be, to be thus visible at a distance of 
ninety- three millions of miles ? 

Outside the sierra are seen, at certain seasons, 
bright, "rose-colored prominences " or flames of enor- 
mous height. During an eclipse, when the dark body 
of the moon comes between the sun and us, exactly 
covering the photosphere, these red tips stand out 
distinctly beyond the edge of sun and moon. Their 
changes have been watched, and their height repeat- 
edly measured. Some are so lofty that ten little earths 
such as ours might be heaped up, one upon another, 
without reaching to their top. Whether they are in 
character at all like the outbursts from our own vol- 
canoes it is hard to say. To compare the two would 
be rather like comparing a small kitchen fire with 
a mighty iron-smelting furnace. The faculse, the 



THE HEAD OE OUR FAMILY. 33 

sierra, and the prominences are visible only through 
a telescope. 

Outside these red flames or " prominences " is the 
corona, commonly divided into the inner and outer 
coronas. 

Many different explanations have been offered of 
this beautiful crown of light round the sun, plainly 
visible to the naked eye during an eclipse. But here 
again we know little, and must be content to watch 
and wait. 
3 



CHAPTER III. 

WHAT BINDS THE FAMILY TOGETHER? 

What is it which binds together all the members 
of the Solar System? Ah, what? Why should not 
the sun at any moment rush away in one direction, 
the earth in a second, the planets in half a dozen 
others? What is there to hinder such a catastrophe? 
Nothing — except that they are all held together by a 
certain close family tie; or, more correctly, by the 
powerful influence of the head of the family. 

This mysterious power which the sun has, and 
which all the planets have also in their smaller de- 
grees, is called Attraction. Sometimes it is named 
Gravitation or Gravity. When we speak, as we often 
do, of the law of attraction or gravitation, we mean 
simply this — that throughout the universe, in things 
little and great, is found a certain wonderful some- 
thing, in constant action, which we call a " law." 
What the "something" may be, man can not tell; 
for he knows it only by its effects. But these effects 
are seen everywhere, on all sides, in the earth and in 
the universe. It is well named in being called a 
"law;" for we are compelled to obey it. None but 
the Divine Lawgiver who made this law can for a sin- 
gle moment suspend its working. 

What causes an apple to fall to the ground when 
it drops from the branch? Why should it not, instead, 
rise upwards? Because, of course, it is heavy, or has 

34 



WHAT BINDS THE FAMILY TOGETHER. 35 

weight. But what is weight? Simply this- — that the 
earth draws or drags everything downwards towards 
herself by the power of attraction. Every substance, 
great or small, light or heavy, is made up of tiny 
atoms. Each one of these atoms attracts or draws 
all the other atoms towards itself; and the closer 
they are together, the more strongly they pull one 
another. 

The atoms in a piece of iron are much closer than 
the atoms in a piece of. wood ; therefore the iron is 
called the "more dense" of the two, and its weight or 
" mass " is greater. The more closely the atoms are 
pressed together, the greater the number of them in 
a small space, and the more strong the drawing to- 
wards the earth ; for the earth draws each one of these 
atoms equally. That is only another way of saying 
that a thing is " heavier." If you drop a stone from 
the top of a cliff, will it rise upwards or float in the 
air? No, indeed. The pull of the earth's attraction, 
dragging and still dragging downward, makes it rush 
through the air, with speed quickening each instant, 
till it strikes the ground. Every single atom in every 
single body pulls every other atom, whether far or 
near. The nearer it is, the stronger always the 
pulling. 

We do not always feel this, because the very much 
greater attraction of the earth hides — or smothers, as 
we may say — the lesser attraction of each small thing 
for another. But though you and I might stand side 
by side upon earth, and feel no mutual attraction, yet 
if we could mount up a few thousands of miles, far 
away from earth, and float in distant space, there we 



36 STORY OF THE SUN, MOON, AND STARS. 

should find ourselves drawn together, and unable to 
remain apart. 

Now precisely as an apple falling from a tree and 
a stone dropping from a cliff are dragged downward 
to the earth, just so our earth and all the planets are 
dragged downwards towards the sun and towards each 
other. The law of the earths attraction of all objects 
on its surface to itself was indistinctly suspected a 
very long time ago; but it was the great Newton who 
first discovered that this same law was to be found 
working among the members of the whole Solar Sys- 
tem. The sun attracts the earth, and the earth at- 
tracts the sun. But the enormous size of the sun 
compared with our earth — like a great nine-foot globe 
beside a tiny one-inch ball — makes our power of at- 
traction to be quite lost sight of in his, which is so 
much greater. 

The principle of gravitation is of far wider scope 
than we have yet indicated. We have spoken merely 
of the attraction of the earth, and we have stated that 
its attraction extends throughout space. But the law 
of gravitation is not so limited. Not only does the 
earth attract every other body, and every other body 
attract the earth, but each of these bodies attracts 
each other; so that, in its more complete shape, the 
law of gravitation announces that " every body in the 
universe attracts every other body with a force which 
varies inversely as the square of the distance." It is 
impossible for us to overestimate the importance of 
this law. It supplies the clue by which we can un- 
ravel the complicated movements of the planets. It 
has led to marvelous discoveries, in which the law of 



WHAT BINDS THE FAMILY TOGETHER. 37 

gravitation has enabled us to anticipate the telescope, 
and, indeed, actually to feel the existence of bodies 
before those bodies have even been seen. 

We come now to another question. If the sun is 
pulling with such power at the earth and all her sis- 
ter planets, why do they not fall down upon him? 
What is to prevent their rolling some day into one of 
those deep rents in his fiery envelope? Did you ever 
tie a ball to a string, and swing it rapidly round and 
round your head? If you did, you must have noticed 
the steady outward pull of the ball. The heavier the 
ball, and the more rapid its whirl, the stronger the pull 
will be. Let the string slip, and the rush of the ball 
through the air to the side of the room will make this 
yet more plain. Did you ever carry a glass of water 
quickly along, and then, on suddenly turning a corner, 
find that the water has not turned with you? It has 
gone on in its former direction, leaving the glass, and 
spilling itself on the floor. 

The cause in both cases is the same. Here is an- 
other "law of nature, " so-called. Though we can 
neither explain nor understand why and how it is so, 
we see it to be one of the fixed rules of God's working 
in every-day life throughout his universe. The law, 
as we see it, seems to be this : Everything which is at 
rest must remain at rest, until set moving by some 
cause outside of, or independent of itself; and every- 
thing which is once set moving, must continue moving 
in a straight line until checked. 

According to this a cannon-ball lying on the ground 
ought to remain there until it is set in motion ; and, 
once set in motion by being fired from a cannon, it ought 



38 STORY OF THE SUN, MOON, AND STARS. 

to go on forever. Exactly so — if nothing stops it. But 
the earth's attraction draws the cannon-ball down- 
ward, and every time it strikes the ground it is partly 
checked. Also each particle of air that touches it 
helps to bring it to rest. If there were no earth 
and no air in the question, the cannon-ball might rush 
on in space for thousands of years. 

Why did the water get spilled ? Because it neces- 
sarily continued moving in a straight line. Your sud- 
den change of direction compelled the solid glass to 
make the same change, but the liquid water was free to 
go straight on in its former course ; so it obeyed this 
law, and did go on. Why did the ball pull hard at the 
string as you swung it round ? Because at each in- 
stant it was striving to obey this same law, and to 
rush onward in a straight line. The pull of the string 
was every moment fighting against that inclination, 
and forcing the ball to move in a circle. 

Just such is the earth's movement in her yearly 
journey round the sun. The string holding in the 
ball pictures the sun's attraction holding in the earth. 
The pulling of the ball outward in order to continue 
its course in a straight line, pictures the pulling of 
our earth each moment to break loose from the sun's 
attraction and to flee away into distant space. 

For the earth is not at rest. Each tick of the clock 
she has sped onward over more than eighteen miles 
of her pathway through the sky. Every instant the 
sun is dragging, with the tremendous force of his at- 
traction, to make her fall nearer to him. Every in- 
stant the earth is dragging with the tremendous force 
of her rapid rush, to get away from him. These two 



WHAT BINDS THE FAMILY TOGETHER. 39 

pullings so far balance each other, or, more strictly, so 
far combine together, that between the two she jour- 
neys steadily round and round in her nearly circular 
orbit. 

If the sun pulled a little harder she would need to 
travel a little faster, or she would gradually go nearer 
to him. If the earth went faster, and the sun's at- 
traction remained the same as it is now, she would 
gradually widen her distance. Indeed, it would only 
be needful for the earth to quicken her pace to 
about five-and-twenty miles a second, the sun's power 
to draw her being unchanged, and she would then 
wander away from him for ever. Day by day we on 
our earth should travel farther and farther away, leav- 
ing behind us all light, all heat, all life, and finding 
ourselves slowly lost in darkness, cold, and death. 

For what should we do without the sun? All our 
light, all our warmth, come from him. Without the 
sun, life could not exist on the earth. Plants, herbage, 
trees, would wither ; the waters of rivers, lakes, oceans, 
would turn to masses of ice ; animals and men would 
die. Our earth would soon be one vast, cold, forsaken 
tomb of darkness and desolation. 

We may not think so, but everything which moves, 
circulates, and lives on our planet is the child of the 
sun. The most nutritious foods come from the sun. 
The wood which warms us in winter is, again, the sun 
in fragments. Every cubic inch, every pound of wood, 
is formed by the power of the sun. The mill which 
turns under the impulse of wind or water, revolves 
only by the sun. And in the black night, under the 
rain or snow, the blind and noisy train, which darts 



4-0 STORY OF THE) SUN, MOON, AND STARS. 

like a flying serpent through the fields, rushes along 
above the valleys, is swallowed up under the mountains, 
goes hissing past the stations, of which the pale eyes 
strike silently through the mist, — in the midst of night 
and cold, this modern animal, produced by human in- 
dustry, is still a child of the sun. The coal from the 
earth which feeds its stomach is solar work, stored up 
during millions of years in the geological strata of 
the globe. 

As it is certain that the force which sets the watch 
in motion is derived from the hand which has wound 
it, so it is certain that all terrestrial power proceeds 
from the sun. It is its heat which maintains the three 
states of bodies — -solid, liquid, and gaseous. The last 
two would vanish, there would be nothing but solids ; 
water and air itself would be in massive blocks, — if 
the solar heat did not maintain them in the fluid state. 
It is the sun which blows in the air, which flows in 
the water, which moans in the tempest, which sings 
in the unwearied throat of the nightingale. It at- 
taches to the sides of the mountains the sources of the 
rivers and glaciers, and consequently the cataracts and 
the avalanches are precipitated with an energy which 
they draw directly from him. Thunder and lightning 
are in their turn a manifestation of his power. Every 
fire which burns and every flame which shines has re- 
ceived its life from the sun. And when two armies 
are hurled together with a crash, each charge of cav- 
alry, each shock between two army corps, is nothing 
else but the misuse of mechanical force from the same 
star. The sun comes to us in the form of heat, he 
leaves us in the form of heat; but between his ar- 



WHAT BINDS THE FAMILY TOGETHER. 41 

rival and his departure, he has given birth to the 
varied powers of our globe. 

I have spoken before about the old-world notion 
that our earth was a fixed plain, with the sun circling 
round her. When the truth dawned slowly upon 
some great minds, anxious only to know what really 
was the truth, others made a hard struggle for the 
older and pleasanter mode of thinking. It went with 
many sorely against the grain to give up all idea of 
the earth being the chief place in the universe. Also 
there was something bewildering and dizzying in the 
notion that our solid world is never for one moment 
still. But truth won the victory at last. Men con- 
sented slowly to give up the past dream, and to learn 
the new lesson put before them. 

We still talk of the sun rising and setting, and of 
the stars doing the same. This is, however, merely a 
common form of speech, which means just the oppo- 
site. For instead of the sun and stars moving, it is 
the earth which moves. 

The earth has two distinct movements. Indeed, I 
ought to say that she has three ; but we will leave all 
thought of the third for the present. First, she turns 
round upon her axis once in every twenty-four hours. 
Secondly, she travels round the sun once in about every 
three hundred and sixty-five days and a quarter. No 
wonder our ancestors were startled to learn that the 
world, which they had counted so immovable, was per- 
petually spinning like a humming-top, and rushing 
through space like an arrow. 

You may gain some clear notions as to the daily 
rising and setting of our sun, with the help of an 



43 STORY OF THF, SUN, MOON, AND STARS. 

orange. Pass a slender knitting-needle through the 
orange, from end to end, and hold it about a yard dis- 
tant from a single candle in a room otherwise darkened. 
Let the needle or axis slant somewhat, and turn the 
orange slowly upon it. 

The candle does not move ; but as the orange turns, 
the candle-light falls in sucession upon each portion 
of the yellow rind. Half of the orange is always in 
shade, and half is always in light ; while at either side, 
if a small fly were standing there, he would be passing 
round out of shade into candle-light, or out of candle- 
light into shade. 

Bach spot on our earth moves round in turn into 
half-light, full-light, half-light, and darkness; or, in 
other words, has morning-dawn, midday-light, evening 
twilight, and night. Each spot on our earth would 
undergo regularly these changes every twenty-four 
hours throughout the year, were it not for another 
arrangement which so far affects this that the North 
and South Poles are, by turns, cut off from the light 
during many months together. 

Thus the sun is in the center of the Solar System, 
turning slowly on his axis; and the earth and the 
planets travel round him, each spinning like a teeto- 
tum, so as to make the most of his bright warm rays. 
But for this spinning movement of the earth, our day 
and night, instead of being each a few hours long, 
would each last six months. 

You may notice that, as you turn the orange steadily 
round, the outside surface of the skin has to move 
much more slowly in those parts close to the knitting- 
needle, than in those parts which bulge out farthest 



WHAT BINDS THE FAMILY TOGETHER. 43 

from it. Near trie North and South Poles the surface 
of our earth travels slowly round a very small circle in 
the course of twenty-four hours. But at the equator 
every piece of ground has to travel about twenty-five 
thousand miles in the same time ; so that it rushes along 
at the rate of more than one thousand miles an hour. 
A man standing on the earth at the equator is being 
carried along at this great speed, not through the air, 
for the whole atmosphere partakes of the same rapid 
motion, but with the air, round and round the earth's 
axis. 

Now about the other movement of the earth — her 
yearly journey round the sun. While she moves, the 
sun, as seen from the earth, seems to change his place. 
First he is observed against a background of one group 
of stars, then against a second, then against a third. 
Not that the stars are visible in the daytime when 
the sun is shining, but their places are well known in 
the heavens; and also they can be noted very soon 
after he sets, or before he rises, so that the constella- 
tions nearest to hirn may each day be easily found out. 

Of course, in old times the sun was thought to be 
really taking this journey among the stars, and men 
talked of " the sun's path " in the heavens. This path 
was named "the Ecliptic," and we use the word still, 
though we know well that the movements are not 
really his, but ours. 

As the earth's daily movement causes day and night, 
so the earth's yearly movement causes spring, summer, 
autumn, and winter. A few pages back I mentioned, 
in passing, one slight yet important fact which lies at 
the root of this matter about the seasons. The earth, 



44 STORY OF THF, SUN, MOON, AND STARS. 

journeying round the sun, travels with her axis slant- 
ing. Put your candle in the middle of the table, and 
stand at one end, holding your orange. Now let the 
knitting-needle, with the orange upon it, so slant that 
one end shall point straight over the candle, towards 
the upper part of the wall at the farther end of the 
room. Call the upper end so pointing the North Pole 
of your orange. You will see that the candle-light 
falls chiefly upon the upper half of the orange ; and as 
you turn it slowly, to picture day and night, you will 
find that the North Pole has no night, and the South 
Pole has no day. That is summer in the northern 
hemisphere, and winter in the southern. 

Walk round next to one side of the table, towards 
the right hand, taking care to let the knitting-needle 
point steadily still in exactly the same direction, not 
towards the same spot, for that would alter its direction 
as you move, but towards the same wall. Stop, and 
you will find the candle lighting up one-half of your 
orange, from the North to the South Poles. Turn it 
slowly, never altering the slope of the axis, and you 
will see that every part of the orange comes by turns 
under the light. This is the Autumnal Equinox, 
when days and nights all over the world are equal in 
length. 

Walk on to the other end of the table, still letting 
the needle slope and point steadily as before. Now 
the candle-light will shine upon the lower or South 
Pole, and the North Pole will be entirely in the shade. 
This is summer in the southern hemisphere, and 
winter in the northern. 

Pass on to the fourth side of the table, and once 



WHAT BINDS THB FAMILY TOGETHER. 45 

more you will find it, as at the second side, equal light 
from North Pole to South Pole. This will be the 
Spring Equinox. 

It is an illustration that may be easily practiced. 
Bug everything depends upon keeping the slant of the 
needle or r.::is unchanged throughout. If it be allowed 
to point first to right, and then to left, first towards the 
ceiling, i/nd then towards the wall, the attempt will 
prove a failure. 



CHAPTER IV. 

THE LEADING MEMBERS OF OUR FAMILY— FIRST 
GROUP. 

The chief distinction between stars and planets is, as 
before said, that the stars shine entirely by their own 
light, while the planets shine chiefly, if not entirely, 
by reflected light. The stars are snns; mighty globes of 
glowing flame. The planets simply receive the light 
of the snn, and shine with a brightness not their own. 

A lamp shines by its own light ; bnt a looking-glass, 
set in the sun's rays and flashing beams in all direc- 
tions, shines by reflected light. In a dark room it would 
be dark. If there were no sun to shine upon Mars or 
Venus, we should see no brightness in them. The 
moon is like the planets in this. She has only bor- 
rowed light to give, and none of her own. 

Any one of the planets removed to the distance of 
the nearest fixed star, would be invisible to us. Re- 
flected light will not shine nearly so far as the direct 
light of a burning body. There may be thousands or 
millions of planets circling round the stars — those 
great and distant suns — just as our brother-planets 
circle round our sun. But it is impossible for us to 
see them. The planets which we can see are close 
neighbors, compared with the stars. I do not mean 
that they are near in the sense in which we speak of 
nearness upon earth. They are only near in compari- 
son with what is so very much farther away. 

46 



LEADING MEMBERS OF OUR FAMILY. 47 

For a while we must now leave alone all thought 
of the distant stars, and try to gain a clear idea of the 
chief members of our own Family Circle — that family 
circle of which the sun is the head, the center, the 
source of life and warmth and light. There are two 
ways in which astronomers group the planets of the 
Solar System. One way is to divide them into the 
Inferior Planets, and the Superior Planets. 

As the earth travels in her pathway round the sun, 
two planets travel on their pathways round the sun 
nearer to him than ourselves. If the pathway or orbit 
of our earth were pictured by a hoop laid upon the 
table, with a ball in the center for the sun; then 
those two planets would have two smaller hoops of 
different sizes within ours; and the rest would have 
larger hoops of different sizes outside ours. The two 
within are called inferior planets, and the rest outside 
are called superior planets. 

A round hoop would not make a good picture of 
an orbit. For the yearly pathway of our earth is not 
in shape perfectly round, but slightly oval; and the 
sun is not exactly in the center, but a little to one side 
of the center. This is more or less the case with the 
orbits of all the planets. 

But the laying of the hoops upon the table would 
give no bad idea of the way in which the orbits really 
lie in the heavens. The orbits of all the chief planets 
do not slope and slant round the sun in all manner of 
directions. They are placed almost in the same plane 
as it is called — or, as we might say, in the same flat. 
In these orbits the planets all travel round in the same 
direction. One may overtake a second on a neighbor- 



48 STORY OF THE SUN, MOON, AND STARS. 

ing orbit, and get ahead of him, but one planet never 
goes back to meet another. 

In speaking of the orbits, I do not mean that the 
planets have visible marked pathways through the 
heavens, any more than a swallow has a visible path- 
way through the sky, or a ship a marked pathway 
through the sea. Yet each planet has his own orbit, 
and each planet so distinctly keeps to his own, that 
astronomers can tell us precisely whereabouts in the 
heavens any particular planet will be, at any particu- 
lar time, long years beforehand. 

There is also another mode of grouping the planets, 
besides dividing them into superior and inferior plan- 
ets. By this other mode we find two principal groups 
or quartets of planets, separated by a zone or belt of a 
great many very small planets. 

( Mercury. 

«"* G ™P \ SrtK 

t Mars. 

The Asteroids or Planetoids. 
C Jupiter. 

Second Group \*g^ 

C Neptune. 

The first four are small compared with the last 
four, though much larger than any in the belt of tiny 
Asteroids. 

It was believed at one time that a planet had been 
discovered nearer to the sun than Mercury, and the 
name Vulcan was given to it. But no more has been 
seen of Vulcan, and his existence is so doubtful that 
we must not count him as a member of the family 
without further information. 



LEADING MEMBERS OE OUR FAMILY. 49 

Mercury is very much smaller than our Earth. The 
diameter of the earth is eight thousand miles, but the 
diameter of Mercury is only about three thousand 
miles — not even half that of the earth. Being so 
much nearer to the sun than ourselves, the pulling of 
his attraction is much greater, and this has to be bal- 
anced by greater speed, or Mercury would soon fall down 
upon the sun. Our distance from the sun is ninety- 
three millions of miles. Mercury's distance is only 
about one-third of ours ; and instead of traveling, like 
the earth, at the rate of eighteen miles each second, 
Mercury dashes headlong through space at the mad 
pace of twenty-nine miles each second. It is a good 
thing the earth does not follow his example, or she 
would soon break loose from the sun's control alto- 
gether. 

The earth takes more than three hundred and sixty- 
five days, or twelve months, to journey round the sun 
in her orbit. That is what we call " the length of our 
year." But Mercury's year is only eighty-eight days, 
or not quite three of our months. No wonder ! — when 
his pathway is so much shorter, and his speed so much 
greater than ours. So Mercury has four years to one 
year on earth; and a person who had lived on Mer- 
cury as long as five earthly years, would then be 
twenty years old. The increased number of birthdays 
would scarcely be welcome in large families, suppos- 
ing we could pay a long visit there. 

The sun, as seen from Mercury, looks about four 
and a half times as large as from here ; the heat and 
glare being increased in proportion. No moon has 
ever been found, belonging to Mercury. 



50 STORY OF the; sun, moon, and stars. 

The planet Mercury is, like the earth and the moon, 
a globe of dark matter which only shines and is visi- 
ble by the illumination of the solar light. Its motion 
round the central star, which brings it sometimes be- 
tween the sun and us, sometimes in an oblique direc- 
tion, sometimes at right angles, and shows us a part 
incessantly variable, of its illuminated hemisphere, 
produces in its aspect, as seen in a telescope, a suc- 
cession of phases similar to those which the moon 



PHASES OF MERCURY BEFORE INFERIOR CONJUNCTION — EVENING 

STAR. 

presents to us. The cut represent the apparent varia- 
tions of size and the succession of phases, visible in 
the evening after sunset; when the planet attains its 
most slender crescent, it is in the region of its orbit 
nearest to the earth, and passes between the sun and 
us ; then, some weeks afterwards, it emerges from the 
solar rays and passes again through the same series 
of phases in inverse order, as we see them by revers- 
ing the figure. 

Venus, the second inferior planet, is nearly the same 
size as our earth. Seen from the earth, she is one of 
the most brilliant and beautiful of all the planets. 



LEADING MEMBERS OE OUR FAMILY. 51 

Her speed is three miles a second faster than ours, 
and her distance from the sun is about two-thirds that 
of our own ; so that the orbit of Venus lies half- 
way between the orbit of Mercury and the orbit 
of the earth. The day of Venus is about half an 
hour shorter than ours. Her year is nearly two hun- 
dred and twenty-five days, or seven and a half of our 
months. One or two astronomers have fancied that 
they caught glimpses of a moon near Venus ; but this 
is still quite doubtful, and indeed it is believed to have 
been a mistake. 

Venus and Mercury are only visible as morning 
and evening planets. Venus, being farther from the 
sun, does not go before and follow after him quite so 
closely as Mercury, and she is therefore the longer 
within sight. 

When Venus, traveling on her orbit, comes just 
between the sun and us, her dark side is turned to- 
wards the earth, and we can catch no glimpse of her. 
When she reaches that part of her orbit which is 
farthest from us, quite on the other side of the sun, 
her great distance from us makes her light seem less. 
But about half-way round on either side, she shows 
exceeding brilliancy, and that is the best view we can 
get of her. 

Seen through a telescope, Venus undergoes phases 
like those of Mercury, or of our moon. That is to 
say, we really have "new Venus," "quarter Venus," 
"half Venus," "full Venus," and so on. 

Of all the luminaries in the heavens, the sun and 
moon excepted, the planet Venus is the most conspic- 
uous and splendid. She appears like a brilliant lamp 



52 

amid the lesser orbs of night, and alternately antici- 
pates the morning dawn, and nshers in the evening 
twilight. When she is to the westward of the snn, in 
winter, she cheers our mornings with her vivid light, 
and is a prelude to the near approach of the break of 
day and the rising sun. When she is eastward of that 
luminary, her light bursts upon us after sunset, before 
any of the other radiant orbs of heaven make their 
appearance; and she discharges, in some measure, the 
functions of the absent moon. The brilliancy of this 
planet has been noticed in all ages, and has been fre- 
quently the subject of description and admiration both 
by shepherds and by poets. The Greek poets distin- 
guished it by the name of Phosphor, "light-bringer," 
when it rose before the sun, and Hesperus, "the west," 
when it appeared in the evening after the sun retired. 
It is now generally distinguished by the name of the 
Morning and Evening Star. 

Next to the orbit of Venus comes the orbit of our 
own Earth, the third planet of the first group. 

Mars, the fourth of the inner quartet, but the first 
of the superior planets, is a good deal smaller than 
Venus or the earth. The name Mars, from the heathen 
god of war, was given on account of his fiery reddish 
color. Mars is better placed than Venus for being 
observed from earth. When he is at the nearest point 
of his orbit to us, we see him full in the blaze of sun- 
light ; whereas Venus, at her nearest point, turns her 
bright face away. 

The length of the day of Mars — or, in other words, 
the time he takes to turn upon his axis- — is only forty 
minutes longer than that of earth. Mars' journey 



SHADING MEMBERS OF OUR FAMILY. 53 

round the sun is completed in the course of six hun- 
dred and eighty-seven days, not much less than two 
of our years. His distance from the sun is about one 
hundred and forty millions of miles, and his speed is 
fourteen miles a second. We shall find, with the in- 
creasing distance of each planet, that the slower pace 
balances the lessened amount of the sun's attraction. 

Passing on from Mars, the last of the first group of 
planets, we reach the belt of Asteroids, sometimes 
called Planetoids, Minor Planets, or Telescopic Planets. 
They are so tiny that Mercury is a giant compared 
with the largest among them. 

The zone of space containing all these little planets 
is more than a hundred millions of miles broad. Their 
orbits do not lie flat in almost the same plane, but 
slant about variously in a very entangled fashion. If 
a neat model were made of this zone, with a slender 
piece of wire to represent each orbit, it would be 
found impossible to lift up one wire without pulling 
up all the rest with it. Those asteroids lying nearest 
to the sun take about three of our years to travel 
round him, and those lying farthest take about six of 
our years. 

New members of the group are very often found. 
The number of asteroids now known amounts to 
about three hundred and twenty. Ceres is estimated 
by Professor Barnard, of the Yerkes Observatory, Chi- 
cago University, to be six hundred miles in diameter. 
Vesta is about two hundred and fifty miles in diameter. 
Meta, on the other hand, is less than seventy-five 
miles. There are some smaller ones that do not 
measure twenty miles in diameter, and it is probable 



54 STORY OF THE SUN, MOON, AND STARS. 

that there are many which are so small as to be ab- 
solutely invisible to the best telescopes, and which 
measure only a few hundred rods in diameter. Twenty 
thousand Vestas would be needed to make one globe 
equal to our earth in size. 

Are they worlds? Why not? Is not a drop of 
water, shown in the microscope, peopled with a mul- 
titude of various beings? Does not a stone in a 
meadow hide a world of swarming insects? Is not 
the leaf of a plant a world for the species which in- 
habit and prey upon it? Doubtless among the mul- 
titude of small planets there are those which must 
remain desert and sterile, because the conditions of 
life (of any kind) are not found united. But we can 
not doubt that on the majority the ever-active forces 
of nature have produced, as in our world, creations 
appropriate to these minute planets. L,et us repeat, 
moreover, that for nature there is neither great nor 
little. And there is no necessity to natter ourselves 
with a supreme disdain for these little worlds ; for in 
reality the inhabitants of Jupiter would have more 
right to despise us than we have to despise Vesta, 
Ceres, Pallas, or Juno. The disparity is greater be- 
tween Jupiter and the earth than between the earth 
and these planets. A world of two, three, or four 
hundred miles in diameter is still a continent worthy 
to satisfy the ambition of a Xerxes or a Tamer- 
lane. 



CHAPTER V. 

THE LEADING MEMBERS OF OUR FAMILY— SECOND 
GROUP. 

Leaving behind us the busy zone of planetoids, 
hurrying round and round the sun in company, we 
cross a wide gap, and come upon a very different 
sight. 

The distance from the sun which we have now 
reached is little less than four hundred and fifty mil- 
lions of miles, or about five times as much as the 
earth's distance; and the sun in the heavens shows a 
diameter only one-fifth of that which we are accus- 
tomed to see. Slowly — yet not slowly — floating on- 
wards through space, in his far-off orbit, we find the 
magnificent planet Jupiter. 

Is eight miles each second slow progress? Com- 
pared with the wild whirl of little Mercury, or even 
compared with the rate of our own earth's advance, 
we may count it so ; but certainly not, compared with 
our notions of speed upon earth. Bight miles each 
second is five hundred times as fast as the swiftest ex- 
press-train^ ever made by man. No mean pace that 
for so enormous a body. For Jupiter is the very 
largest of all the members of the Solar System except 
the sun himself — quite the eldest brother of the fam- 
ily. His diameter is about eighty-five thousand miles, 
his axis being nearly eleven times as long as that of 
earth. Though in proportion to his great bulk not 

55 



56 STORY OF THE SUN, MOON, AND STARS. 

nearly so heavy as our earth, yet his bulk is so vast 
that more than twelve hundred earths would be needed 
to make one Jupiter. 

It must not, however, be forgotten that there is a 
certain amount of uncertainty about these measure- 
ments of Jupiter. He seems to be so covered with a 
dense atmosphere and heavy clouds that it is quite 
impossible for us to learn the exact size of the solid 
body within. 

Jupiter does not travel alone. Borne onwards with 
him, and circling steadily around him, are five moons; 
the smallest with a probable diameter of about one hun- 
dred miles ; one about the same size as our own moon, 
and the others all larger. The nearest of the five, 
though distant from the center of the planet over one 
hundred and twelve thousand miles, revolves about 
him in twelve hours ; the second, though farther from 
Jupiter than our moon from the earth, speeds round 
him in less than two of our days. The most distant, 
though over a million miles away, takes scarcely seven- 
teen days to accomplish its long journey. Jupiter and 
his moons make a little system by themselves — a 
family circle within a family circle. 

Like the smaller planets, Jupiter spins upon his 
axis ; and he does this so rapidly that, notwithstanding 
his great size, his day lasts only ten hours, instead of 
twenty-four hours like ours. But if Jupiter's day is 
short, his year is not. Nearly twelve of our years pass 
by before Jupiter has traveled once completely round 
the sun. So a native of earth who had just reached 
his thirty -seventh year, would, on Jupiter, be only 
three years old. 



LEADING MEMBERS OE OUR EAMIEY. 57 

Passing onward from Jupiter, ever farther and 
farther from the sun, we leave behind us another vast 
and empty space — empty as we count emptiness, 
though it may be that there is in reality no such thing 
as emptiness throughout the length and breadth of 
the universe. The width of the gap which divides 
the pathway of Jupiter from the pathway of his giant 
brother-planet Saturn is nearly five times as much as 
the width of the gap separating the earth from the 
sun. The distance of Saturn from the sun is cot 
much less than double the distance of Jupiter. 

With this great space in our rear, we come upon 
another large and radiant planet, the center, like Ju- 
piter, of another little system ; though it can only be 
called "little" in comparison with the much greater 
Solar System of which it forms a part. 

Saturn's diameter is less than that of Jupiter, but 
the two come near enough to be naturally ranked to- 
gether. Nearly seven hundred earths would be needed 
to make one globe as large as Saturn. But here again 
the dense and cloudy envelope makes us very uncertain 
about the planet's actual size. Saturn is like Jupiter 
in being made of lighter materials than our earth; 
and also in his rapid whirl upon his axis, the length 
of his "day" being only ten and a half of our hours. 

From Jupiter's speed of eight miles each second, 
we come down in the case of Saturn to only five miles 
each second. And Jupiter's long annual journey looks 
almost short, seen beside Saturn's long journey of 
thirty earthly years. A man aged sixty, according to 
our fashion of reckoning time, would on Saturn have 
just kept his second birthday. 



5» 

The system or family of Saturn is yet more won- 
derful than that of Jupiter. Not five only but eight 
moons travel ceaselessly round Saturn, each in its own 
orbit; and in addition to the eight moons, he has 
revolving round him three magnificent rings. These 
rings, as well as the moons, shine, not by their own 
brilliancy, for they have none, but by borrowed sun- 
light. The farthest of the moons wanders in his 
lonely pathway about two millions of miles away from 
Saturn. The largest of them is believed to be about 
the same size as the planet Mars. Of the three rings 
circling round Saturn, almost exactly over his equator, 
the inside one is dusky, purplish, and transparent ; the 
one outside or over that is very brilliant; and the 
third, outside the second, is rather grayish in hue. 

Another vast gap — more enormous than the last. 
It is a wearisome journey. From the orbit of Jupiter 
to the orbit of Saturn at their nearest points, was five 
times as much as from the sun to the earth. But from 
the orbit of Saturn to the orbit of Uranus, the next 
member of the sun's family, we have double even that 
great space to cross. 

Still, obedient to the pulling of the sun's attractive 
power, Uranus wanders onward in his wide pathway 
round the sun, at the rate of four miles a second. 
Kighty-four of our years make one year of Uranus. 
This planet has four moons, and thus forms a third 
smaller system within the Solar System ; but he may 
have other satellites also, as yet undiscovered. In size 
he is seventy-four times as large as our earth. 

One more mighty chasm of nine hundred millions 
of miles, for the same distance which separates the 



LEADING MEMBERS OE OUR FAMILY. 59 

pathway of Saturn from the pathway of Uranus, sep- 
arates also the pathway of Uranus from the pathway 
of Neptune. Cold, and dark, and dreary indeed seems 
to us the orbit on which this banished member of our 
family circle creeps round the sun, in the course of one 
hundred and sixty-five years, at the sluggish rate of 
three miles a second. 

On the planet Saturn, the quantity of light and 
heat received from the sun is not much more than a 
hundredth part of that which we are accustomed to 
receive on earth. But by the time we reach Neptune, 
the great sun has faded and shrunk in the distance 
until to our eyes he looks only like an exceedingly 
brilliant and dazzling star. 

We know little of this far-off brother, Neptune, 
except that he is rather larger than Uranus, being one 
hundred and five times as big as the earth; that he has 
at least one moon; and also that, like Uranus, he is 
made of materials lighter than those of earth, but 
heavier than those of Jupiter or Saturn. 

After all, it is no easy matter to gain clear ideas as 
to sizes and distances from mere statements of "so 
many miles in diameter," and "so many millions of 
miles away." A "million miles" carries to the mind 
a very dim notion of the actual reality. 

Now if we can in imagination bring down all the 
members of the Solar System to a small size, keeping 
always the same proportions, we may find it a help. 
"Keeping the same proportions" means that all must 
be lessened alike, all must be altered in the same 
degree. Whatever the supposed size of the earth may 
be, Venus must be still about the same size as the 



60 STORY OF THE SUN, MOON, AND STARS. 

earth, Saturn seven hundred times as large, and so on, 
Also, whatever the distance of the earth from the sun, 
in miles, or yards, or inches, Mercury must still be one- 
third as far, Jupiter still five times as far, and thus 
with the rest. 

First, as to size alone. Suppose the earth is repre- 
sented by a small globe, exactly three inches in diam- 
eter. It will be a very small globe. Not only men 
and houses, but mountains, valleys, seas, will all have 
to be reduced to so minute a size, as to be quite invisi- 
ble to the naked eye. 

Fairly to picture the other members of the Solar 
System, in due proportion, you will have them as 
follows : 

Mercury and Mars will be balls smaller than the 
earth, and Venus nearly the same size of the earth. 
Uranus and Neptune will be each somewhere about a 
foot in diameter. Saturn will be twenty-eight inches 
and Jupiter thirty-two inches in diameter. The sun 
will be a huge dazzling globe, twenty-six feet in di- 
ameter. No wonder he weighs seven hundred and 
fifty times as much as all his planets put together. 

Next let us picture the system more exactly on 
another and smaller scale. First, think of the sun as 
a brilliant globe, about nine feet, or three yards, in 
diameter, floating in space. 

About one hundred yards from the sun travels a 
tiny ball, not half an inch in diameter, passing slowly 
round the sun — slowly, because as sizes and distances 
are lessened, speed must in due proportion be lessened 
also. This is Mercury. About two hundred yards 
from the sun travels another tiny ball, one inch in di- 



LEADING MEMBERS OF OUR FAMILY. 6l 

ameter. This is Venus. Nearly a quarter of a mile 
from the sun travels a third tiny ball, one inch again 
in diameter; and at a distance of two feet and a half 
from it a still smaller ball, one quarter of an inch in 
diameter, journeys round it and with it. These are 
the earth and the moon. About half as far again as 
the last-named ball, travels another, over half an inch 
in diameter. This is Mars. 

Then comes a wide blank space, followed by a large 
number of minute objects, no bigger than grains of 
powder, floating round the sun in company. These 
are the Asteroids. Another wide blank space suc- 
ceeds the outermost of them. 

About one mile distant from the sun journeys a 
globe, ten inches in diameter. Round him, as he 
journeys, there travel five smaller balls, the largest of 
which is about the third of an inch in diameter. Their 
distances from the bigger globe vary from one and a 
third to twelve and a half feet. These are Jupiter and 
his moons. 

Nearly two miles distant from the sun journeys 
another globe, about eight and a half inches in diam- 
eter. Eight tiny balls and three delicate rings circle 
round him as he moves. These are Saturn and his 
belongings. About four miles distant from the sun 
journeys another globe, four inches in diameter, with 
four tiny balls accompanying him — Uranus and his 
moons. Lastly, at a distance of six miles from the 
sun, one more globe, not much larger than the last, 
with one tiny companion, pursues his far-off pathway. 

These proportions as to size and distance will serve 
to give a clear idea of the Solar System. 



CHAPTER VI. 

THE MOON. 

Come, and let us pay a visit to the moon. We 
seem to feel a personal interest in her, just because 
she is, in so peculiar a sense, our own friend and close 
attendant. The sun shines for us ; but, then, he shines 
for all the members of the Solar System. And the 
stars — so many as we can see of them — shine for us 
too; but no doubt they shine far more brilliantly for 
other and nearer worlds. The moon alone seems to 
belong especially to ourselves. 

Indeed, we are quite in the habit of speaking about 
her as "our moon." Rather a cold and calm friend, 
some may think her, sailing always serenely past, 
whatever may be going on beneath her beams; yet 
she has certainly proved herself constant and faithful 
in her attachment. 

We have not very far to travel before reaching her, 
— merely about two hundred and forty thousand miles. 
That is nothing, compared with the weary millions of 
miles which we have had to cross to visit some mem- 
bers of our family. A rope two hundred and forty 
thousand miles long would fold nearly ten times round 
the earth at the equator. You know the earth's di- 
ameter — about eight thousand miles. If you had 
thirty poles, each eight thousand miles long, and 
could fasten them all together, end to end, one beyond 
another, you would have a rod long enough to reach 
from the earth to the moon. 

62 



THE MOON. 



63 



Let us take a good look at her before starting. She 
is very beautiful. That soft silvery light, so unlike 
sunlight or gaslight, or any other kind of light seen 
upon earth, has made her the darling of poets and 
the delight of all who love nature. Little children 
like to watch her curious markings, and to make out 




APPEARANCE OF THE) FUU, MOON. 

the old man with his bundle of sticks, or the eyes, 
nose, and mouth of the moon — not dreaming what 
those markings really are. And in moods of sadness, 
how the pure calm moonlight seems to soothe the 
feelings ! Who would suppose that the moon's beauty 
is the beauty rather of death than of life ? 

The stars have not much chance of shining through 
her bright rays. It is well for astronomers that she is 
not always at the full. But when she is, how large 
she looks — qvtite as large as the sun, though in reality 



64 STORY OF THE SUN, MOON, AND STARS. 

her size, compared with, his, is only as a very small 
pin's head compared with a school globe two feet in 
diameter. Her diameter is little more than two thou- 
sand miles, or one quatrer that of our earth; and her 
whole surface, spread out flat, would scarcely equal 
North and South America, without any of the sur- 
rounding islands. 

The reason she looks the same size as the sun, is 
that she is so very much nearer. The sun's distance 
from us is more than one-third as many millions of 
miles as the moon's distance is thousands of miles. 
This makes an enormous difference. 

We call our friend a " moon," and say that she 
journeys round the earth, while the earth journeys 
round the sun. This is true, but it is only part of the 
truth. Just as certainly as the earth travels round 
the sun, so the moon also travels round the sun. And 
just as surely as the earth is a planet, so the moon also 
is a planet. It is a common mode of expression to 
talk about " the earth and her satellite." A no less 
correct, if not more correct, way would be to talk of 
ourselves as "a pair of planets," journeying round the 
same sun, each pulled strongly towards him, and each 
pulling the other with a greater or less attraction, ac- 
cording to her size and weight. For the sun actually 
does draw the moon with more force than that with 
which the earth draws her. Only as he draws the 
earth with the same sort of force, and nearly in the 
same degree, he does not pull them apart. 

The moon, like the other planets, turns upon her 
axis. She does this very slowly, however; and most 
singularly she takes exactly the same time to turn 



THK MOON. 65 

once upon her axis that she does to travel once round 
the earth. The result of this is, that we only see one 
face of the moon. If she turned upon her axis, 
and journeyed round the earth in two different lengths 
of time, or if she journeyed round us and did not turn 
upon her axis at all, we should have views of her on 
all sides, as of other planets. But as her two move- 
ments so curiously agree, it happens that we always 
have one side of the moon towards us, and never catch 
a glimpse of the other side. 

And now we are ready to start on our journey of 
two hundred and forty thousand miles. An express 
train, moving ceaselessly onward night and day, at the 
rate of sixty miles an hour, would take us there in 
about five months and a half. But no line of rails has 
ever yet been laid from the earth to the moon, and no 
" Flying Dutchman " has ever yet plied its way to and 
fro on that path through the heavens. Not on the 
wings of steam, but on the wings of imagination, we 
must rise aloft. Come — it will not take us long. We 
shall pass no planets or stars on the road, for the moon 
lies nearer to us than any other of the larger heavenly 
bodies. 

Far, far behind us lies the earth, and beneath our 
feet, as we descend, stretch the broad tracts of moon- 
land. For " downward" now means towards the 
moon, and away from the distant earth. 

What a strange place we have reached! The weird, 
ghastly stillness of all around, and the glaring, daz- 
zling, cloudless heat, strike us first and most forcibly. 
Nothing like this heat have we ever felt on earth. For 
the close of the moon's long day — on this side of its 
5 



66 STORY OF TH3 SUN, MOON, AND STARS. 

globe — is approaching, and during a whole fortnight 
past the sun's fierce rays have been beating down on 
these shelterless plains. Talk of sweltering tropics on 
earth! What do you call this heat? Look at the 
thermometer : how the quicksilver is rising ! Well, that 
is not a common thermometer which we have brought 
with us. The mercury has stopped — three hundred 
degrees above boiling water! 

Not a cloud to be seen overhead ; only a sky of inky 
blackness, with a blazing sun, and thousands of brill- 
iant stars, and the dark body of our own earth, large 
and motionless, and rimmed with light. Seen from 
earth, sun and moon look much the same size; but 
seen from the moon, the earth looks thirteen times as 
large as our full moon. Not even a little mistiness in 
the air to soften this fearful glare ! Air ! why, there 
is no air ; at least not enough for any human being to 
breathe or feel. If there were air, the sky would be 
blue, not black, and the stars would be invisible in 
the daytime. It looks strange to see them now shining 
beside the sun. 

And then, this deadly stillness! Not a sound, not 
a voice, not a murmur of breeze or water. How could 
there be ? Sound can not be carried without air, and 
of air there is none. As for breeze — wind is moving 
air, and where we have no air we can have no wind. 
As for water — if there ever was any water on the 
moon, it has entirely disappeared. We shall walk to 
and fro vainly in search of it now. No rivers, no rills, 
no torrents in those stern mountain ramparts rising on 
every side. All is craggy, motionless, desolate. 

How very, very slowly the sun creeps over the black 



THE MOON. 6j 

sky! And no marvel, since a fortnight of earth-time 
is here bnt one day, answering to twelve hours upon 
earth. Can not we find shelter somewhere from this 
blazing heat? Yonder tall rock will do, casting a sharp 
shadow of intense blackness. We never saw such 
shadows upon earth. There the atmosphere so breaks 
and bends and scatters about the light, that outlines 
of shadows are soft and hazy, even the clearest and 
darkest of them, compared with this. 

When will the sun go down? But he is well worth 
looking at meanwhile. How magnificent he appears, 
with his pure radiant photosphere, fringed by a sierra 
of dazzling pink and white, orange and gold, purple 
and blue. For here no atmosphere lies between to 
blend all into yellow-white brightness. And how 
plainly stand out those prominences or tongues of 
tinted flame, not merely rose-colored, as seen from 
earth, but matching the sierra in varying hues ; while 
beyond spreads a gorgeous belt of pink and green, 
bounded by lines and streams of delicate white light, 
reaching far and dying slowly out against the jet back- 
ground. The black spots on the face of the sun are 
very distinct, and so also are the brilliant faculae. 

We must take a look around us now at moonland, 
and not only sit gazing at the sun, though such a sky 
may well enchain attention. How unlike our earthly 
landscapes! No sea, no rivers, no lakes, no streams, 
no brooks, no trees, bushes, plants, grass, or flowers; 
no wind or breeze ; no cloud or mist or thought of pos- 
sible rain; no sound of bird or insect, of rustling 
leaves or trickling water. Nothing but burning, stead- 
fast, changeless glare, contrasting with inky shadows; 



68 STORY OF THE SUN, MOON, AND STARS. 

sun and earth and stars in a black heaven above; 
silent, desolate mountains and plains below. 

For though we stand here upon a rough plain, this 
moon is a mountainous world. Ranges of rugged 
hills stretch away in the distance, with valleys lying 
between — not soft, green, sloping, earthly valleys, but 
steep gorges and precipitous hollows, all white dazzle 
and deep shade. 

But the mountains do not commonly lie in long 
ranges, as on earth. The surface of the moon seems 
to be dented with strange round pits, or craters, of 
every imaginable size. We had a bird's-eye view of 
them as we descended at the end of our long journey 
moonward. In many parts the ground appears to be 
quite honeycombed with them. Here are small ones 
near at hand, and larger ones in the distance. The 
smaller craters are surrounded by steep ramparts of 
rock, the larger ones by circular mountain-ranges. We 
have nothing quite like them on earth. 

Are they volcanoes? So it would seem; only no 
life, no fire, no action, remain now. All is dead, 
motionless, still. Is this verily a blasted world ? Has 
it fallen under the breath of Almighty wrath, com- 
ing out scorched and seared ? Is it simply passing 
through a certain burnt-out, chilled phase of existence, 
through which other planets also pass, or will pass, at 
some stage of their career? Who can tell? 

We will move onward, and look more closely at 
that towering mass of rugged rocks, beyond which the 
sun will by and by go down. Long jetty shadows lie 
from them in this direction. No wonder astronomers 
on earth can through their telescopes plainly see these 



THE MOON. 



6 9 



black shadows contrasting with the glaring brightness 
on the other side. 

A "mass of rocks" I have said; but as, with our 
powers of rapid movement, we draw near, we find a 
range of craggy mountains sweeping round in a vast 
circle. Such a height in Switzerland would demand 
many hours of hard climbing. But on this small 
globe attraction 



is a very differ- 
ent matter from 
what it is on 
earth; our weight 
is so lessened 
that we can leap 
the height of a 
tall house with- 
out the smallest 
difficulty. No 
chamois ever 
sprang from 
peak to peak in 
his native Switzerland with such amazing lightness as 
that with which we now ascend these mighty rocks. 
Ha! what a depth on the other side! We stand 
looking down into one of the monster craters of the 
moon. A sheer descent of at least eleven thousand 
feet would land us at the bottom. Why, Mont Blanc 
itself is only about fifteen thousand feet in height. 
And what a crater ! Fifty-six miles across in a straight 
line, from here to the other side, with these lofty 
rugged battlements circling round, while from the 
center of the rough plain below a sharp, cone-shaped 




ONE FORM OP I,UNAR CRATER. 



JO STORY OF THE SUN, MOON, AND STARS. 

mountain rises to about a quarter of the height of the 
surrounding range. 

It is a grand sight; peak piled upon peak, crag upon 
crag, sharp rifts or valleys breaking here and there the 
line of the narrow, uplifted ledge ; all wrapped in silent 
and desolate calm. There are many such craters as 
this on the moon, and some much larger. 

The sun slowly nears his setting, and sinks behind 
the opposite range. How we shiver ! The last ray of 
sunlight has gone and already the ground is pouring 
out its heat into space, unchecked by the presence of 
air or clouds. The change takes place with marvelous 
quickness. A deadly chill creeps over all around. A 
whole fortnight of earth-time must pass before the 
sun's rays will again touch this spot. Verily the con- 
trasts of climate in the moon, during the twelve long 
days and nights which make up her year, are startling 
to human notions. 

But though the sun is gone we are not in darkness. 
The stars shine with dazzling brightness, and the huge 
body of the earth, always seeming to hang motionless 
at one fixed point in the sky, gives brilliant light, 
though at present only half her face is lit up and half 
is in shadow. Still her shape is plainly to be seen, 
for she has ever round her a ring of light, caused by 
the gathered shining of stars as they pass behind her 
thick atmosphere. She covers a space on the sky 
more than a dozen times as large as that covered by 
the full moon in our sky. 

It would be worth while to stay here and watch the 
half-earth grow into magnificent full-earth. But the 
cold is becoming fearful — too intense for even the 




THE EARTH AS SEEN FROM THE MOON, 

7i 



72 STORY OF THE SUN, MOON, AND STARS. 

imagination to endure longer. What must be the state 
of things on the other side of the moon, where there 
is no bright earth-light to take the place of the sun's 
shining, during the long two weeks' night of awful 
chill and darkness? 

It seems probable that a building on the moon 
would remain for century after century just as it was 
left by the builders. There need be no glass in the 
windows, for there is no wind and no rain to keep 
out. There need not be fireplaces in the rooms, for 
fuel can not burn without air. Dwellers in a city in 
the moon would find that no dust can rise, no odors 
be perceived, no sounds be heard. Man is a creature 
adapted for life in circumstances which are very nar- 
rowly limited. A few degrees of temperature, more 
or less ; a slight variation in the composition of air, 
the precise suitability of food, make all the difference 
between health and sickness, between life and death. 
Looking beyond the moon, into the length and breadth 
of the universe, we find countless celestial globes, with 
every conceivable variety of temperature and of con- 
stitution. Amid this vast number of worlds with 
which space teems, are there any inhabited by living 
beings ? To this great question science can make no 
response save this: We can not tell. 

Time for us to wend our way homewards from this 
desolate hundred-fold arctic scene. We have more to 
learn by and by about our friend and companion. 
For the present — enough. 



CHAPTER VII. 

VISITORS. 

WE come next to the very largest members of our 
Solar System. 

From time to time in past days — and days not 
very long past either — people were startled by the 
sight of a long-tailed star, moving quickly across the 
sky, called a comet. We see such long-tailed stars 
still, now and then; but their appearance no longer 
startles us. 

It is hardly surprising, however, that fears were 
once felt. The great size and brilliancy of some of 
these comets naturally caused large ideas to be held 
as to their weight, and the general uncertainty about 
their movements naturally added to the mysterious 
notions afloat with respect to their power of doing 
harm. 

A collision between the earth and a comet seemed 
no unlikely event; and if it happened — what then? 
Why, then, of course, the earth would be overpowered, 
crushed, burnt up, destroyed. So convinced were 
many on this point that the sight of a comet and the 
dread of the coming "end of the world" were fast 
bound together in their minds. 

Even when astronomers began to understand the 
paths of some of the comets, and to foretell their re- 
turn at certain dates, the old fear was not quickly laid 
to rest. So late as the beginning of the present cen- 

73 



74 STORY OF THE SUN, MOON, AND STARS. 

tury, astronomers having told of an approaching 
comet, other people added the tidings of an approach- 
ing collision. "If a collision, then the end of the 
world, " was the cry; and one worthy family, living 
and keeping a shop in a well-known town on the 
south coast of England, packed up and fled to Amer- 
ica — doubtless under full belief that the destruction 
of the Old World would not include the destruction 
of the New. 

The nature of these singular bodies is somewhat 
better known in the present day ; yet even now, among 
all the members of the Solar System, they are perhaps 
the ones about which we have most to learn. The 
nucleus, or bright and star-like spot, which, with the 
surrounding coma or "hair," we sometimes call the 
"head" of the comet, is the densest and heaviest part 
of the whole. The comets are of immense size, some- 
times actually filling more space than the sun him- 
self, and their tails stream often for millions of miles 
behind them ; nevertheless, they appear to be among 
the lightest of the members of the Solar System. 

This excessive lightness greatly lessens the comet's 
power of harm-doing. In the rebound from all the 
old exaggerated fears, men laughed at the notion of 
so light and delicate a substance working any injury 
whatever, and even declared that a collision might 
take place without people on earth being aware of 
the fact. It is now felt that we really know too little 
about the nature of the said substance to be able to 
say what might or might not be the result of a col- 
lision. A certain amount of injury to the surface of 
the earth might possibly take place. But of the 



visitors. 75 

" end of the world," as likely to be brought about 
by any comet in existence, we may safely banish 
all idea. 

The word "comet" means "a hairy body," the 
name having been given from the hairy appearance 
of the light around the nucleus. About seventeen 
hundred different comets have been seen at different 
times by men — some large, some small ; some visible 
to the naked eye, but most of them only visible through 
telescopes. These hundreds are, there is no doubt, but 
a very small number out of the myriads ranging through 
the heavens. 

If you were seated in a little boat in mid-ocean, 
counting the number of fishes which in one hour 
passed near enough in the clear water for your sight 
to reach them, you might fairly conclude, even if you 
did not know the fact, that for every single fish which 
you could see, there were tens of thousands which you 
could not see. 

Reasoning thus about the comets, as we watch 
them from our earth-boat in the ocean of space, we 
feel little doubt that for each one which we can see, 
millions pass to and fro beyond reach of our vision. 
Indeed, so long ago as the days of Kepler, that great 
astronomer gave it as his belief that the comets in 
the Solar System, large and small, were as plentiful 
as the fishes in the sea. And all that modern as- 
tronomers can discover only tends to strengthen this 
view. 

Why should the comets be called "visitors?" I 
call them so simply because many of them are visitors. 
Some, it is true, belong to the Solar System. But 



76 STORY OF THE SUN, MOON, AND STARS. 

even in their case, strong donbts are felt whether they 
were not once visitors from a distance, caught in the 
first instance by the attraction of one of the larger 
planets, and retained thenceforward, for a time at least, 
by the strong attraction of the sun. 

Every comet, like every planet, has his own orbit 
or pathway in the heavens, though the kind of orbit 




PASSAGE OF THE EARTH AND THE MOON THROUGH THE TAII, OF A 

COMET. 

varies with different comets. There are, first, those 
comets which travel round and round the sun in 
"closed orbits" — that is, in a ring with joined ends. 
Only the ring is always oval, not round. There are, 
secondly, those which travel in an orbit which may be 
closed; but if so, the oval is so long and narrow, and 
the farther closed end is at so great a distance, that 
we can not speak certainly. There are, thirdly, those 
which decidedly are mere visitors. They come from 
the far-off star-depths, flash once with their brilliant 
trains of light through our busy Solar System, causing 



VISITORS. J7 

some little excitement by the way, and go off in an- 
other direction, never to return. 

Only a small part of the orbits of these comets can 
be seen from earth ; but by careful attention astrono- 
mers learn something of the shape of the curve in 
which they travel. It is in that way possible to cal- 
culate, sometimes certainly, and sometimes uncer- 
tainly, whether a comet may be expected to return, or 
whether we have seen him for the first and the last 
time. By looking at part of a curve, the rest of 
which is hidden from us, we are able to judge 
whether that part belongs to a circle or an oval, or 
whether the two ends pass away in different direc- 
tions, and do not join. 

The comets, whether members of our family circle 
or visitors from a distance, are altogether very perplex- 
ing. They are often extremely large, yet they are al- 
ways extremely light. They reflect the sun's bright- 
ness like a planet, yet in some measure they seem to 
shine by their own light, like a star. They obey the 
attraction of the sun, yet he appears to have a singu- 
lar power of driving the comets' tails away from 
himself. 

For, however rapidly the comet may be rushing 
round the sun, and however long the tail may be, it is 
almost always found to stream in an opposite direction 
from the sun. An exception to this rule was seen in 
the case of a certain comet with two tails, one of 
which did actually point towards the sun ; but the in- 
ner tail may have been only a " jet" of unusual length, 
like in kind to the smaller jets often thus poured out 
from the nucleus. 



yS STORY OF THE SUN, MOON, AND STARS. 

Very curious changes take place in comets as they 
journey, especially as they come near the sun. One 
was seen in the course of a few days to lose all his 
hair, and also his tail. Another was seen to break 
into two pieces, both of which pieces at last disap- 
peared. Sometimes the one tail divides into two tails. 

Traveling, as the comets do, from intense cold into 
burning heat, they are very much affected by the vio- 
lent change of climate. For the paths of the comets 
are such long ovals, or ellipses, that, while they ap- 
proach the sun very closely in one part of their "year," 
they travel to enormous distances in the other part. 

" Halley's Comet," which takes seventy-six of our 
years to journey round the sun, comes nearer to him 
than Venus, and goes farther away from him than 
Neptune. As this comet draws gradually closer, he 
has to make up for the added pull of the sun's in- 
creasing attraction by rushing onward with greater 
and greater rapidity, till he whirls madly past the sun, 
and then, with slowly slackening speed, journeys far- 
ther and farther away, creeps at length lazily round 
the farther end of his orbit in the chill, dark, neigh- 
borhood of Neptune, and once more travels towards 
the sun with growing haste. 

"Encke's Comet" has a year of only three and a 
half of our years, so he may be said to live quite in 
our midst. But many comets travel much farther 
away than the one named after Halley. It is calcu- 
lated of some that, if they ever return at all, it can not 
be for many hundreds of years. 

11 Newton's Comet," seen about two centuries ago, 
has a journey to perform of such length that he is 



VISITORS. 



79 



not expected again to appear for several thousand 
years. Yet, at the nearest point in his orbit, he ap- 
proached the sun so closely, that the heat which he 




PASSAGE OF THE COMET OF 1843 CLOSE TO THE SUN (FEBRUARY 
27TH, IO HOURS, 29 MINUTES.) 



endured was about two thousand times that of red- 
hot iron. Changes were seen to be taking place in 
his shape, as he drew near to the sun, and disappeared. 
Four days he was hidden in the sun's rays. He van- 
ished, with a tail streaming millions of miles behind 



80 STORY OF THE SUN, MOON, AND STARS. 

him. He made his appearance again with a tail 
streaming millions of miles in front of him. Bnt how 
this wonderful movement took place is beyond man's 
power to explain. 

The comet of 1843 was one of the most attractive 
seen during the present century. It was first observed 
in March, and it appeared with a suddenness which had 
quite a startling effect. It was an imposing object in 
the southern regions. The comet was seen in Italy 
on the 28th of February; at Washington, on the 6th 
of March ; at Oporto, on the 14th ; but owing to unfa- 
vorable weather, it was not visible in England, or any 
of the northern countries of Europe, previous to the 
17th. A little after sunset on that day the tail was 
observed in the western sky, but the head had already 
sunk below the horizon. The whole of the comet ap- 
peared on the following evenings for a short time, for 
it was traveling away from the sun with great veloc- 
ity, having doubled the solar orb before it became 
visible; and about the beginning of April it finally 
disappeared. 

The appearance of this startling stranger, as ob- 
served at Washington, is thus described by Lieuten- 
ant Maury, of the Hydrographical Office in that city: 
u On Monday morning, March 6th, our attention was 
called to a paragraph in the newspapers, stating that 
a comet was visible near the sun at midday with the 
naked eye. The sky was clear; but not being able to 
discover any thing with the unassisted eye, recourse 
was had to the telescope, but with no better success. 
About sunset in the evening, the examination was re- 
newed with great diligence, but to no purpose. The 



VISITORS. 8l 

last faint streak of day gilded the west; beautiful 
and delicate fleeces of cloud curtained the bed of 
the sun; the upper sky was studded with stars, 
and all hopes of seeing the comet that evening had 
vanished. Soon after we had retired, the officer of 
the watch announced its appearance in the west. The 
phenomenon was sublime and beautiful. The needle 
was greatly agitated, and a strongly marked pencil of 
light was streaming up from the path of the sun in 
an oblique direction to the southward and eastward; 
its edges were parallel. It was 30 long. Stars 
could be seen twinkling through it, and no doubt 
was at first entertained that this was the tail of the 
comet. ,, 

The tail, as seen in northerly countries, spread over 
an arc of the heavens of about 40 ; but in southern 
latitudes it extended to from 6o° to 70 . It had an ab- 
solute length of two hundred millions of miles; so 
that, had it been coiled around the earth like a serpent, 
it would have girdled it eight thousand times at the 
equator. This comet approached still nearer the sun 
than that of Newton, and must therefore have been 
exposed to a heat of greater intensity. Its center is 
computed to have been within a hundred thousand 
miles of the solar surface ; and according to Sir John 
Herschel's calculations, it was then exposed to a heat 
equal to that which would be received by an equal 
portion of the earth's service, if it were subject to the 
influence of forty-seven thousand suns, placed at the 
common distance of the actual sun. It is difficult to 
conceive how a flimsy substance in such circumstances 
could escape being entirely dissipated. But such was 
6 



82 STORY OF THE SUN, MOON, AND STARS. 

its velocity that it wheeled round the sun in less than 
two hours. 

The general question of the probability and the 
consequences of a collision with a comet may be legit- 
imately entertained. With reference to the first point, 
it can not be denied that collision is possible ; but, at 
the same time, it is so extremely improbable that it 
may be safely dismissed from apprehension. The fact 
of such an event not having been experienced in the 
known course of terrestrial history is surely some 
guarantee against its occurrence. Another may be 
found in the small volume of the earth and of comets 
when compared with the immensity of space in which 
they move. According to the well-understood prin- 
ciples of probabilities, Arago has calculated that, upon 
the appearance of a new comet, the odds are as 281,- 
000,000 to 1, that it will not strike against our globe. 
But even supposing collision to occur, all that we 
know of the constitution of comets justifies the con- 
clusion that the encounter would involve no terrestrial 
convulsion, nor any result incompatible with full se- 
curity to life and happiness. 

So much for the largest members of our circle — 
largest, though lightest; members some, visitors oth- 
ers. Now we turn to the smallest. 



CHAPTER VIII. 

LITTLE SERVANTS. 

If you walk out any night after dark, and watch 
the bright stars shining in a clear sky — shining as 
they have done for ages past — you will probably see, 
now and then, a bright point of light suddenly appear, 
dart along a little distance, and as suddenly vanish. 
That which you have seen was not the beginning of 
a story, but in ninety-nine cases out of a hundred 
it was the end of a story. The little shooting-star 
was in existence t long before you saw him, whirling 
through space with millions of little companions. But 
he has left them all, and dropped to earth. He is a 
shooting-star no longer. 

If such a journey to the moon as the one described 
two chapters back were indeed possible, the voyage 
aloft would hardly be so easily and safely performed 
as is there taken for granted. Putting aside the 
thought of other difficulties, such as lack of convey- 
ance and lack of air, there would be the danger of 
passing through a very considerable storm of mis- 
siles — a kind of " celestial cannonade" — which, to say 
the least, would prove very far from agreeable. 

These " starlets" and " meteor planets," as they 
have been called, are not visible in a normal condition, 
because of their minuteness. But on entering our at- 
mosphere they are rendered luminous, owing to the 
heat evolved by the sudden and violent compression 

83 



84 STORY OF THE SUN, MOON, AND STARS. 

of the air in front of the moving body. According to 
this view, shooting-stars, which simply dart across the 
heavens, may be regarded as coming within the limits 
of the atmosphere, and carried out of it again, by their 
immense velocity, passing on in space. Meteoric 




METEOR EMERGING FROM BEHIND A CI^OUD (NOV. 23, 1877). 

showers may result from an encounter with a group 
of these bodies, while aerolites are those which come 
so far within the sphere of the earth's attraction as to 
fall to its surface. More than two thousand years ago 
the Greeks venerated a famous stone which fell from 
the heavens on the river iBgos. 

It will scarcely be believed what numbers of these 
shooting-stars or meteorites constantly fall to the earth. 
As she travels on her orbit, hurrying along at the rate 
of nineteen miles each second, she meets them by 



LITTLE SERVANTS. 85 

tens of thousands. They too, like the earth, are jour- 
neying round the great center of our family. But 
they are so tiny, and the earth by comparison is so 
immense, that her strong attraction overpowers one 
after another, drags it from its pathway, and draws it 
to herself. 

And then it falls, flashing like a bright star across 
the sky, and the little meteorite has come to his end. 
His myriads of companions, hastening still along their 
heavenly track — for the meteorites seem to travel com- 
monly in vast flocks or companies — might, had they 
sense, mourn in vain for the lost members of their 
family. 

Any one taking the trouble to watch carefully some 
portion of the sky after dark, may expect to see each 
hour about four to eight of these shooting-stars — ex- 
cept in the months of August and November, when 
the number is much larger. About six in an hour 
does not sound a great deal. But that merely means 
that there have been six in one direction, and near 
enough for you to see. Somebody else, watching, 
may have seen six in another direction; and some- 
body else, a few miles away, may have seen six more. 
It is calculated that, in the course of every twenty- 
four hours, about four hundred millions of meteorites 
fall to earth, including those visible only through 
telescopes. 

This is rather startling. What if you or I should 
some day be struck by one of these solid, hard little 
bodies, darting as they do towards earth with speed 
swifter than that of a cannon-ball? True, they are 
not really stars, neither are they really planets. But 



86 STORY OF THE SUN, MOON, AND STARS. 

they are, to say the least, often much larger than a 
cannon-ball, and a cannon-ball can destroy life. 

Four hundred millions every twenty-four hours! 
Does it not seem singular that we do not see them 
constantly dropping to the ground? The truth is, we 
should see them, and feel them too, and dire would 
be the danger to human life, but for a certain pro- 
tecting something folded round this earth of ours to 
ward off the peril. That "something" is the earth's 
atmosphere. But for the thick, soft, strong, elastic 
air through which the meteorites have to pass, they 
would fall with fearful violence, often doing terrible 
mischief. As it is, we are guarded. The shooting- 
star, drawn by the earth's attraction, drops into her 
atmosphere, darting with tremendous speed. In con- 
sequence of this speed and the resistance of the air, 
it catches fire. That is when we first see it. The 
meteorites are believed to appear at a height of about 
seventy miles, and to disappear at a height of about 
fifty miles. So that, in one instant's flash, the shoot- 
ing-star has traveled some twenty miles toward us. 
Then the light goes out. The little meteorite is burnt. 
It falls to earth still; but only as fine dust, sinking 
harmlessly downward. 

The meteorites do not always vanish so quickly. 
Now and then a larger one — too large to be rapidly 
burnt — does actually reach the ground. If any man 
were struck by such a stone he would undoubtedly be 
killed. 

When meteorites thus fall to earth they are usually 
called aerolites. Some are found no bigger than a 
man's fist, while others much exceed this size. There 



LITTLE SERVANTS. 87 

is one, kept carefully in the British Museum, which 
weighs three tons and a half; and we hear of another, 
lying in South America, between seven and eight feet 
in length. Such a sky-visitant would be very unwel- 
come in any of our towns. 

We must remember that, whatever size an aerolite 
may be when it reaches the earth, it must have been 
far greater when journeying round the sun, since a 
good part of it has been burnt away during its rush 
downward through the earth's atmosphere. 

Meteors, or bolides, or fireballs, are of much the 
same nature as meteorites; but they are larger, longer 
to be seen, and slower in movement. Also, it is not 
uncommon for them to burst with a loud explosion. 
Early in the present century such a meteor visited 
Normandy. It exploded with a noise like the roll of 
musketry, scattering thousands of hot stones over a 
distance of several miles. A great number of them 
were collected, still smoking. The largest of these 
stones weighed no less than twenty pounds. Hap- 
pily no one seems to have been injured. Other such 
falls have taken place from time to time. Sometimes 
bright, slowly-moving meteors have been seen, looking 
as large as the moon. 

A remarkable fireball appeared in England on 
November 6, 1869. This fireball was extensively 
seen from different parts of the island, and by com- 
bining and comparing these observations, we obtain 
accurate information as to the height of the object 
and the velocity with which it traveled. It appears 
that this meteor commenced to be visible at a point 
ninety miles above Frome, in Somersetshire, and that 



88 STORY OF THE SUN, MOON, AND STARS. 

it disappeared at a point twenty-seven miles over the 
sea, near St. Ives, in Cornwall. The whole length of 
its course was about 170 miles, which was performed 
in a period of five seconds, thus giving an average ve- 
locity of thirty-four miles a second. A remarkable 
feature in the appearance which this fireball pre- 
sented was the long, persistent streak of luminous 
cloud, about fifty miles long and four miles wide, 
which remained in sight for fully fifty minutes. We 
have in this example an illustration of the chief fea- 
tures of the phenomena of a shooting-star presented 
on a very grand scale. It is, however, to be observed 
that the persistent luminous streak is not a universal, 
nor, indeed, a very common characteristic of a shoot- 
ing-star. 

If we may liken comets to the fishes of the Solar 
System — and in their number, their speed, their vary- 
ing sizes, their diverse motions, they may be fairly so 
likened — we may perhaps speak of the meteorites as 
the animalcula of the Solar System. For, in com- 
parison with the planets, they are, in the matter of 
size, as the animalcula of our ponds in comparison 
with human beings. In point of numbers they are 
countless. 

Take a single drop of water from some long-stag- 
nant pond, and place it under a powerful microscope. 
You will find it to be full of life, teeming with tiny ani- 
mals, darting briskly to and fro. The drop of water 
is in itself a world of living creatures, though the 
naked eye of man could never discover their existence. 
So with the meteorites. There is good reason to be- 
lieve that the Solar System fairly teems with them. 



LITTLE SERVANTS. 89 

We talk of "wide gaps of empty space," between the 
planets; bnt how do we know that there is any snch 
thing as empty space to be found throughout all the 
sun's domain? 

Not only are the meteorites themselves countless, a 
matter easily realized, but the families or systems of 
meteorites appear to be countless also. They, like 
the systems of Jupiter and Saturn, are each a family 
within a family — a part of the Solar System, and yet 
a complete system by themselves. Each circles round 
the sun, and each consists of millions of tiny meteor- 
ites. When I say "tiny," I mean it of course only by 
comparison with other -heavenly bodies. Many among 
them may possibly be hundreds of feet and even more 
in diameter, but the greater proportion appear to be 
much smaller. It is not impossible that multitudes 
beyond imagination exist, so small in size that it is 
impossible we should ever see them, since their 
dying flash in the upper regions of our atmosphere 
would be too faint to reach our sight. 

The earth, traveling on her narrow orbit round the 
sun, crosses the track of about one hundred of these 
systems, or rings. Sometimes she merely touches the 
edge of a ring, and sometimes she goes into the very 
thick of a dense shower of meteorites. Twice every 
year, for instance, on the 10th of August and the nth 
of November, the earth passes through such a ring, 
and very many falling stars may be seen on those 
nights. Numbers of little meteorites, dragged from 
their orbits and entangled in the earth's atmosphere, 
like a fly caught in a spider's web, give their dying 
flash, and vanish. It used to be supposed that the 



9 o 



STORY OF THE SUN, MOON, AND STARS. 



August and November meteorites belonged to one 
single system ; but now they are believed to be two 
entirely distinct systems. 

The comet discovered on February 27, 1827, by 
Biela, and ten days later at Marseilles by Gambart, 
who recognized that it was the same as that of 1772 




THE GREAT SHOWER OF SHOOTING-STARS, NOVEMBER 27, 1872. 

and 1805, returned six and a half years later, in 1832. 
In fact it crossed, as we have seen, the plane of the 
terrestrial orbit at the respectable distance of fifty 
millions of miles from the earth; but if there was 
any danger in this meeting, it was rather for it than 
for us; for it was certainly strongly disturbed in its 
course. It returned in 1839, but under conditions 
too unfavorable to enable it to be observed — in the 
month of July, in the long days, and too near the 
sun. It was seen again in 1845, on November 



LITTLK SERVANTS. 91 

25th, near the place assigned to it by calculation, and 
its course was duly followed. Everything went on to 
the general satisfaction, when — unexpected spectacle! 
— on January 13, 1846, the comet split into two! What 
had passed in its bosom? Why this separation? What 
was the cause of such a celestial cataclysm? We do 
not know; but the fact is, that instead of one comet, 
two were henceforth seen, which continued to move 
in space like two twin-sisters — two veritable comets, 
each having its nucleus, its head, its coma, and its 
tail, slowly separating from each other. On February 
10th there was already a hundred and fifty thousand 
miles of space between the two. They would seem, 
however, to have parted with regret, and during sev- 
eral days a sort of bridge was seen thrown from one 
to the other. The cometary couple, departing from 
the earth, soon disappeared in the infinite night. 

They returned within view of the earth in the 
month of September, 1852. On the 26th of this 
month the twins reappeared, but much farther apart, 
separated by an interval of twelve hundred and fifty 
thousand miles. 

But this is not the strangest peculiarity which this 
curious body presented to the attention of astronomers. 
The catastrophe which was observed in 1846 was only 
a presage of the fate which awaited it; for now its ex- 
istence is merely imagined, the truth being that this 
comet is lost. Since 1852 all attempts to find it again 
have been unavailing. 

To be lost is interesting, especially for a comet. 
But this, doubtless, was not enough; for it reserved 
for us a still more complete surprise. Its orbit inter- 



92 STORY OF THE SUN, MOON, AND STARS. 

sects the terrestrial orbit at a point which the earth 
passes on November 27th. Well, nothing more was 
thought about it — it was given up as hopeless, when, 
on the evening of November 27, 1872, there fell from 
the sky a veritable rain of shooting stars. The ex- 
pression is not exaggerated. They fell in great flakes. 
Lines of fire glided almost vertically in swarms and 
showers — here, with dazzling globes of light; there, 
with silent explosions, recalling to mind those of rock- 
ets; and this rain lasted from seven o'clock in the 
evening till one o'clock next morning, the maximum 
being attained about nine o'clock. At the observatory 
of the Roman College, 13,892 were counted; at Mont- 
calieri, 33,400; in England a single observer counted 
10,579, etc. The total number seen was estimated at 
a hundred and sixty thousand. They all came from the 
same point of the sky, situated near the beautiful star 
Gamma of Andromeda. 

On that evening I happened to be at Rome, in the 
quarter of the Villa Medicis, and was favored with a 
balcony looking towards the south. This wonderful 
rain of stars fell almost before my eyes, so to say, and 
I shall never cease regretting not having seen it. 
Convalescent from a fever caught in the Pontine 
Marshes, I was obliged to go into the house immedi- 
ately after the setting of the sun, which on that even- 
ing appeared from the top of the Coliseum to sleep in 
a bed of purple and gold: My readers will understand 
what disappointment I felt next morning when, on go- 
ing to the observatory, Father Secchi informed me of 
that event! How had he observed it himself? By 
the most fortunate chance : A friend of his, seeing the 



LITTLE SERVANTS. 93 

stars fall, went to him to ask an explanation of such a 
phenomenon. It was then half-past seven. The spec- 
tacle had commenced; but it was far from being fin- 
ished, and the illustrious astronomer was enabled to 
view the marvelous shower of nearly fourteen thousand 
meteors. 

This event made a considerable stir in Rome, and 
the pope himself did not remain indifferent ; for, some 
days afterwards, having had the honor of being re- 
ceived at the Vatican, the first words that Pius IX ad- 
dressed to me were these: " Have you seen the shower 
of Danae?" I had admired, some days before in 
Rome, some admirable "Danaes," painted by the 
great masters of the Italian school in a manner which 
left nothing to be desired; but I had not had the 
privilege of finding myself under the cupola of the 
sky during this new celestial shower, more beautiful 
even than that of Jupiter. 

What was this shower of stars? Evidently — and 
this is not doubtful — the encounter with the earth of 
myriads of small particles of matter moving in space 
along the orbit of Biela's comet. The comet itself, 
if it still existed, would have passed twelve weeks be- 
fore. It was not, then, to speak correctly, the comet 
itself which we encountered, but perhaps a fraction 
of its decomposed parts, which, since the breaking-up 
of the comet in 1846, would be dispersed along its 
orbit behind the head of the comet.* 



* No doubt can remain of the identity of this swarm of shoot- 
ing-stars with the cotfiet of Biela. On November 27, 1885, the 
same encounter occurred. A magnificent shower of stars was ob- 
served all over Europe just at the moment when the earth crossed 
the comet's orbit. 



94 STORY OF THE SUN, MOON, AND STARS. 

Once in every thirty-three years we have a grand 
display of meteorites in November ; tens of thousands 
being visible in one single night. The meteorites in 
that ring have their "year" of thirty-three earthly 
years, and once in the course of that long year our 
earth's orbit carries her deep into their midst. In 
this single November ring there are myriads upon 
myriads of meteorites, spreading through millions of 
miles of space. 

Yet this system is but one among many. There is 
no reason whatever to suppose that the streams of me- 
teorites cluster more thickly about the orbit of the 
earth, than in other parts of the Solar System. No 
doubt the rest of the planets come across quite as 
many. Indeed, the wonderful rings of Saturn are 
probably formed entirely of meteorites — millions upon 
millions of them whirling round the planet in a reg- 
ular orbit-belt, lit up by the rays of the sun. Also it is 
believed that the meteorite families cluster more and 
more closely in the near neighborhood of the sun, 
rushing wildly round him, and falling by millions into 
the ocean of flame upon his surface. It has even been 
guessed that they may serve in part as fuel to keep up 
his mighty furnace heat. 

There is a curious cone-shaped light seen some- 
times in the west after sunset. It is called the "Zo- 
diacal L,ight," and men have often been much puzzled 
to account for it. The shining is soft and dim, only 
to be seen when the sky is clear, and only to be seen 
in the neighborhood of the sun. This, too, may be 
caused by reflected light from countless myriads of 
meteorites gathering thickly round the sun. 



CHAPTER IX. 

NEIGHBORING FAMILIES. 

WE have now to take flight in thought far, far be- 
yond the outskirts of our little Solar System. Yes, 
our great Solar System, with its mighty sun, its 
planets, its moons, its comets and meteorites, its 
ceaseless motions, its vast distances, — even all this 
sinks to littleness beside the wider reaches of space 
which now have to be pictured to our minds. For 
our sun, in all his greatness, is only a single star — - 
only one star among other stars — and not by any 
means one of the largest of the stars. 

How many stars are there in the sky? I^ook over- 
head some cloudless night, and try to count the brill- 
iant points of light. " Millions," you would most 
likely give as your idea of their number. Yet you 
would be wrong; for you do not really perceive so 
many. The stars visible to man's naked eye have 
been mapped and numbered. It is found that from 
two to three thousand are, as a rule, the utmost ever 
seen at once, even on a favorable night, and with par- 
ticularly good sight. 

But what is actually the full number of the stars? 
Two or three thousand overhead. Five or six thou- 
sand round the whole world. So much visible to 
man's unaided eyes. Ah, but take a telescope, and 
see through it the opening fields of stars beyond stars. 
Take a stronger telescope, and note how, as you pierce 

95 



96 STORY OF THE SUN, MOON, AND STARS. 

deeper into space, fresh stars beyond fresh stars shine 
faintly in the measnreless distance. Take the most 
powerful telescope ever made, and again it will be the 
same story. 

There has been a chart or map drawn of known 
stars in the northern hemisphere — including those 
visible in telescopes down to a certain magnitude — 
containing over three hundred thousand. But that is 
only a part of even what man can see. Sir William 
Herschel calculated roughly that the number of stars 
within reach of his powerful telescope, round the 
whole earth, amounted probably to something like 
twenty millions. 

Twenty millions of suns ! For that is what it really 
means. Twenty millions of radiant, burning, heav- 
enly bodies — some the same size as our sun; some 
larger, perhaps very much larger ; some smaller, per- 
haps very much smaller; but all suns. And any 
number of these suns may have, just like our own, 
families of planets traveling round them, enjoying 
their light and their heat. 

We talk about stars of the first, second, and other 
magnitudes. Stars can be seen without a telescope 
as low down as the sixth magnitude ; after that they 
become invisible to the naked eye. This word " mag- 
nitude " is rather misleading. "Magnitude" means 
size, and whatever the real size of the stars may be, 
they have to our sight no seeming size at all. So 
when we speak of different magnitudes, we really 
mean different brightnesses. The brightest stars are 
those of the first magnitude, the next brightest those 
of the second magnitude, and so on. No doubt many 



NEIGHBORING FAMILIES. 97 

a star of the third or fourth magnitude is really much 
larger than many a star of the first or second magni- 
tude, only being farther away it shines more dimly, or 
the higher-magnitude star may in itself possess greater 
natural brilliancy. 

Of first-magnitude stars there are altogether about 
twenty; of second-magnitude stars about sixty-five; 
of third-magnitude stars about two hundred; and so 
the numbers increase till of the sixth-magnitude stars 
we find more than three thousand. These are all that 
can be commonly seen with the naked eye, amounting 
to five or six thousand. With telescopes the numbers 
rise rapidly to tens of thousands, hundreds of thou- 
sands, and even millions. 

For a long while it was found quite impossible to 
measure the distances of the stars. To this day the 
distances of not over two dozen, among all those tens 
of thousands, have been discovered. The difficulty of 
finding out the distance of the sun was as nothing 
compared with the difficulty of finding out the dis- 
tances of the stars. 

No base-line sufficient for the purpose could for 
years be obtained. I must explain slightly what is 
meant by a " base-line. " Suppose you were on the 
brink of a wide river, which you had no means of 
crossing, though you wished to discover its breadth. 
Suppose there were on the opposite brink a small 
tree, standing alone. As you stood, you would see 
the tree seeming to lie against a certain part of the 
country beyond. Then, if you moved along your 
bank some fifty paces, the tree would seem to lie 
against quite a different part of the country beyond. 
7 



98 STORY OF THE SUN, MOON, AND STARS. 

Now if you had a long piece of string to lay down 
along the fifty paces yon walked, and if two more 
pieces of string were tied, one from each end of the 
fifty paces, both meeting at the tree, then the three 
pieces of string would make one large triangle, and 
the " fifty paces" would be the "base" of your tri- 
angle. 

If you could not cross the river, you could not of 
course tie strings to the tree. But having found your 
base-line, and measured its exact length, and having 
also found the shape of the two angles at its two ends, 
by noting the seeming change of the tree's position, 
it would then be quite easy to find out the distance 
of the tree. The exact manner in which this calcula- 
tion is made can hardly be understood without some 
slight knowledge of a science called trigonometry. 
The tree's distance being found, the breadth of the river 
would be known. 

This mode of measuring distance was found com- 
paratively easy in the case of the moon. But in the 
case of the sun there was more difficulty, on account 
of the sun's greater distance. No base-line of ordinary 
length would make the sun seem to change his posi- 
tion in the sky in the slightest degree. Nor till the 
very longest base-line on the earth was tried could the 
difficulty be overcome. That base-line is no less than 
eight thousand miles long. One man standing in 
England looking at the sun, and another man stand- 
ing in Australia looking at the sun, have such a base- 
line lying between them, straight through the center 
of the earth. 

In the case of the stars this plan was found useless. 



NEIGHBORING FAMILIES. 99 

So closely has the sky been mapped out, and so ex- 
actly is the place of each star known, that the tiniest 
change would have been at once noticed. Not a star 
showed the smallest movement. The eight thousand 
miles of the earth's diameter was a mere point with 
regard to them. 

A bright idea came up. Here was our earth trav- 
eling round the sun, in an orbit so wide that in the 
middle of summer she is over one hundred and eighty 
millions of miles away from where she is in the mid- 
dle of winter. Would not that make a magnificent 
base-line? Why not observe a star in summer and 
observe the same star again in winter, and then calcu- 
late its distance. 

This, too, was done. For a long while in vain! 
The stars showed no signs of change, beyond those due 
to causes already known. Astronomers persevered, 
however, and with close and earnest care and improved 
instruments, success at last rewarded their efforts. 
A few — only a few, but still a few — of those distant 
suns have submitted to the little measuring-line of 
earth, and their distance has been roughly calculated. 

Now, what is their distance? Alpha Centauri, the 
second star which was attempted with success, is the 
nearest of all whose distance we know. You have 
heard how far the sun is from the earth. The dis- 
tance of Alpha Centauri is two hundred and seventy-five 
thousand times as much. Can you picture to yourself 
that vast reach of space — a line ninety-three millions 
of miles long, repeated over and over again two hun- 
dred and seventy-five thousand times ? 

But Alpha Centauri is one of the very nearest. 



IOO STORY OF THE SUN, MOON, AND STARS. 

The brilliant Sirius is at least twice as far away. 
Others utterly refuse to show the smallest change 
of position. It is with them, as had been said, much 
the same as if a man were to look at a church- 
steeple, twenty miles distant, out of one pane in a 
window, and then were to look at it out of the next 
pane. With the utmost attention he would find no 
change of position in the steeple. And like the base- 
line of two glass panes to that steeple, so is the base- 
line formed by our whole yearly journey to thousands 
of distant stars. We might measure how far away 
they are, only the longest base-line within our reach 
is too short for our purpose. 

The planet Neptune has a wider orbit than ours. 
But even his orbit, seen from the greater number of 
the stars, would shrink to a single point. After all, 
how useless to talk of two hundred and seventy-five 
thousand times ninety-three millions of miles ! What 
does it mean? We can not grasp the thought. 

Let us look at the matter from another view. Do 
you know how fast light travels — this bright light 
shining round us all day long? Light, so far as we 
know, does not exist everywhere. It travels to and 
fro, from the sun to his planets, from the planets to 
one another ; from the sun to the moon, from the 
moon to the earth, and from the earth to the moon 
again. 

Light takes time to travel. This sounds singular, 
but it is true. Light can not pass from place to place 
in no time. Light, journeying through space, is invis- 
ible. Only when it strikes upon something, whether 
a solid body or water or air, does it become visible to 



NEIGHBORING FAMILIES. IOI 

our eyes. The shining all round us in the day-time 
is caused by the sunlight being reflected, not only 
from the ground, but from each separate particle of air. 
If we had no atmosphere, we should see still the bright 
rays falling on the ground, but the sky above would 
be black. Yet that black sky would be full of mil- 
lions of light-rays, journeying hither and thither from 
sun and stars, invisible except where they alight upon 
something. 

The speed of light is far beyond that of an express 
train, far beyond that of the swiftest planet. In one 
tick of the clock, Mercury has rushed onward twenty- 
nine miles. In one tick of the clock, storm-flames 
upon the surface of the sun will sweep over two or 
three hundred miles. But in one tick of the clock a 
ray of light flashes through one hundred and eighty- 
six thousand three hundred and thirty-seven miles. 

One hundred and eighty-six thousand miles ! That 
is the same as to say that, during one single instant, 
a ray of light can journey a distance equal to about 
eight times round and round our whole earth at the 
Equator. 

By using this wonderful light-speed as a measure- 
ment, we gain clearer ideas about the distances of the 
stars. A ray of light takes more than eight minutes 
to pass from the sun to the earth. L,ook at your watch, 
and note the exact time. See the hand moving slowly 
through the minutes, and imagine one single ray of 
light, which has left the sun when first you looked, 
flashing onward and onward through space, one hun- 
dred and eighty-six thousand miles each second. Eight 
minutes and a half are over. The ray falls upon your 



102 STORY OF THE SUN, MOON, AND STARS. 

hand. In those few minntes it has journeyed ninety- 
three millions of miles. 

So much for the sun's distance. How about the 
stars? Alpha Centauri, a bright star seen in the 
southern hemisphere, is one of our nearest neighbors. 
Yet each light-gleam which reaches the eye of man 
from that star, left Alpha Centauri four years and a 
third before. During four years and a third, from the 
moment when first it quitted the surface of the blazing 
sun, it has flashed ceaselessly onward, one hundred 
and eighty-six thousand miles each second, dwindling 
down with its bright companion-rays from a glare of 
brilliancy to a slender glimmer of light till it reaches 
the eye of man. Four years and a third sounds much, 
side by side with the eight minutes' journey from the 
sun. Sound would take more than three millions of 
years to cross the same abyss. At the constant ve- 
locity of thirty-seven miles an hour, an express-train 
starting from the sun Alpha Centauri would not reach 
the earth until after an uninterrupted course of nearly 
seventy-five millions of years. 

This is our neighbor star. The second, the near- 
est after it, is nearly double as far, and is found in 
quite another region of space, in the constellation of 
Cygnus, the Swan, always visible in our northern 
hemisphere. If we wish to understand the relative 
situation of our sun and the nearest two, let us take 
a celestial globe, and draw a plane through the center 
of the globe and through Alpha Centauri and 61 
Cygni. We shall thus have before us the relation 
which exists between our position in infinitude and 
those of these two suns. The angular distance which 



NEIGHBORING FAMILIES. IO3 

separates them on the celestial sphere is 125 . Let 
us make this drawing, and we shall discover certain 
rather curious particulars. In the first place, these 
two nearest stars are in the plane of the Milky Way, 
so that we can also represent the Milky Way on our 
drawing; again, this celestial river is divided into 
two branches, precisely in the positions occupied by 
these two nearest stars, the division remaining marked 
along the whole interval which separates them. This 
drawing shows us, further, that if we wish to trace the 
curve of the Milky Way with reference to the distance 
of our two stars, it will be nearer to us in the con- 
stellation of the Centaur than in that of the Swan ; 
and, in fact, it is probable that the stars of that region 
of the sky are nearer than those of the opposite re- 
gion. Another very curious fact is, that both the 
nearest stars are double. 

But look at Sirius, that beautiful star so familiar to 
us all. The light which reaches you to-night, left his 
surface from nine to ten years ago. Look at the Little 
Bear, with the Pole-star shining at the end of his tail. 
That ray of soft light quitted the Pole-star some forty 
years ago. Almost half a century it has been speed- 
ing onward and ever onward, with ceaseless rapidity, 
till its vast journey is so far accomplished that it has 
reached the earth. Look at Capella, another fair star 
of the first magnitnde. The light which reaches you 
from her has taken over thirty years to perform its 
voyage. Ten, thirty, forty years — at the rate of 
186,000 miles per second! 

These stars are among the few whose distance can 
be roughly measured. Others lie at incalculable dis- 



104 STORY OF THE SUN, MOON, AND STARS. 

tances beyond. There are stars whose light must, it 
is believed, have started hundreds or even thousands 
of years before the soft, faint ray at length reaches 
the astronomer's upturned eye through the telescope. 

Look at Capella, how gently and steadily she 
shines! You see Capella, not as she is now, but as 
she was thirty years ago. Capella may have ceased 
to exist meantime. The fires of that mighty sun 
may have gone out. If so, we shall by and by learn 
the fact — more than thirty years after it happened. 
Look at the Pole-star. Is there any Pole-star now? 
I can not tell you. I only know there was one, forty 
years ago, when that ray of light started on its long 
journey. Stars have ceased to shine before now. 
What may have happened in those forty years, who 
can say? Look at that dim star, shining through a 
powerful telescope with faint and glimmering light. 
We are told that in all probability the tiny ray left its 
home long before the time of Adam. 

There is a strange solemnity in the thought. Hun- 
dreds of years ago — thousands of years ago — -some say, 
even tens or hundreds of thousands of years ago ! It 
carries us out of the little present into the unknown 
ages of a past eternity. 

If the neighboring stars are placed at tens and 
hundreds of trillions of miles from us, it is at quad- 
rillions, at quintillions of miles that most of the stars 
lie which are visible in the sky in telescopic fields. 
What suns! what splendors! Their light comes from 
such distances ! And it is these distant suns which 
human pride would like to make revolve round our 
atom ; and it was for our eyes that ancient theology 



< NEIGHBORING FAMILIES. 105 

declared these lights, invisible without a telescope, 
were created ! No contemplation expands the thought, 
elevates the mind, and spreads the wings of the soul 
like that of the sidereal immensities illuminated by 
the suns of infinitude. We are already learning that 
there is in the stellar world a diversity no less great 
than that which we noticed in the planetary world. 
As in our own Solar System the globes already studied 
range from 6 miles in diameter (satellites of Mars) 
up to 88,ooo miles (Jupiter) — that is to say, in the 
proportion of I to 14,000 — so in the sidereal system 
the suns present the most enormous differences of 
volume and brightness: 61 Cygni, the stars numbered 
2,398 in the catalogue of Lalande, and 9,352 in the 
catalogue of L,acaille, and others of the eighth or ninth 
magnitude, are incomparably smaller or less luminous 
than Sirius, Arcturus, Capella, Canopus, Rigel, and 
the other brilliants of the firmament. 



CHAPTER X. 

OUR NEIGHBORS' MOVEMENTS. 

How high ! how distant ! how mighty ! How little 
we know about them, yet how overwhelming the little 
we know, and how wonderful that we do know it! 

We have now to consider the movements of these 
distant neighbors — first, their seeming movements; 
secondly, their real movements. 

I have already spoken about the seeming motions 
of the stars as a whole, once believed to be real, and 
now known to be only caused by the motions of our 
earth. For just as the turning of the earth upon her 
axis makes the sun seem to rise every morning in the 
east, and to set every evening in the west, so that 
same continued turning makes the stars seem to rise 
every evening in the east and to set every morning in 
the west. 

When we speak of the stars as rising in the east, 
we do not mean that they all rise at one point in the 
east, but that all rise, more or less, in an easterly di- 
rection — northeast, east, and southeast. So also with 
respect to the west. It is to the east and west of the 
earth as a whole that they rise and set — not merely to 
the east and west of that particular spot on earth 
where one man may be standing. All night long fresh 
stars are rising, and others are setting, and if it were 
not for the veil of light made by the sunshine in our 
atmosphere, we should see the same going on all day 
long as well. 

106 



our neighbors' movements. 107 

There are some constellations, or groups of stars, 
always visible at night in our northern hemisphere ; 
and there are some constellations never visible to us, 
but only seen by people living in the southern hemi- 
sphere — in Australia, for instance. There are other 
constellations which appear in summer and disappear 
in winter, or which appear in winter and disappear in 
summer. This change is caused by our earth's jour- 
ney round the sun. It is not that the constellations 
have altered their place in the heavens with respect 
to the other constellations, it is merely that the earth 
has so altered its position in the heavens that the 
groups of stars which a short time ago were above the 
horizon with the sun by day are now above the hori- 
zon without him by night. 

Mention has been a good many times made of the 
axis of the earth ending in the North and South Poles. 
If this axis were carried straight onward through 
space, a long, slender pole passing upwards into the 
sky without any bend, from the North Pole in one 
direction and from the South Pole in the other, — this 
would be the pole of the heavens. The places of the 
stars in the sky are counted as "so many degrees" 
from the North and South Celestial Poles, just as the 
places of towns on earth are counted as "so many 
degrees" from the North and South Poles of earth. 
There are atlases of the sky made as well as atlases of 
the earth. 

The constellation of the Great Bear is known to all 
who have ever used their eyes at all to watch the 
heavens. Almost equally well known are the two 
bright stars in this constellation named the Pointers, 



108 STORY OF THE SUN, MOON, AND STARS. 

because, taken together, they point in nearly a straight 
line to a certain important star in the end of the Little 
Bear's tail, not very distant. 

This star, important less from its brightness than 
from its position, lies close to that very spot in the 
heavens where the celestial North Pole passes. It is 
called the Pole-star. Night after night, through the 
year, it there remains, all but motionless, never going 
below the horizon for us in the northern hemisphere, 
or northern half of the earth ; never rising above the 




CONSTEIXATION OF THE GREAT BEAR. 

horizon for those in the southern hemisphere. It 
shines ever softly and steadily in its fixed position. 
If you travel further south, the Pole-star sinks down- 
ward towards the horizon. If you travel further 
north, the Pole-star rises higher above the horizon. 
If you were at the North Pole, you would see the Pole- 
star exactly overhead. 

Very near the Pole-star is the constellation of the 
Great Bear, with Cassiopeia nearly opposite on the 
other side of the Little Bear, and other groups be- 
tween the two, completing the circle. These con- 
stellations do not, to us who live in the northern 
hemisphere, rise or set; for they simply move in a 



OUR neighbors' movements. 



109 



circle round and round the Pole-star, never going be- 
low the horizon. All day and all night long this 
circling movement continues, though only visible at 




THE GREAT BEAR 50,000 YEARS AGO. 

night. It is caused entirely by the earth's own motion 
on her axis. 

Lower down, or rather further off from the Pole- 
star, comes another ring of constellations. These in 




THE GREAT BEAR 50,000 YEARS HENCE. 

just the same manner appear to travel round and 
round the Pole-star. But being further away, each 
dips in turn below the horizon — or, as we call it, each 
sets and rises again. And by the time we come to 
yet another circle of leading constellations, we reach 



IIO STORY OF THE SUN, MOON, AND STARS. 

those which are so far affected by the earth's yearly 
journey as to be only visible through certain months, 
and to be hidden during other months. 

If we could stand exactly at the North Pole, during 
part of its six months' night, we should see the Pole- 
star just overhead, and all the constellations circling 
round it once in every twenty-four hours. Those 




CONSTKIXATION OF ORION, AS IT APPEARS NOW. 

nearest would move slowly, in a small ring. Those 
furthest, and lowest down, would in the same length 
of time sweep round the whole horizon. But the 
stars would not there seem to rise or set. If we were 
standing at the South Pole, we should see exactly the 
same kind of seeming movement, only with altogether 
a different set of stars. If we were standing on the 
Equator at night, we should see the rising and set- 
ting very plainly. The whole mass of stars would 
appear to rise regularly and evenly in an easterly di- 
rection, to pass steadily across the sky, each taking 



OUR neighbors' movements. 



Ill 



its own straightforward path, and to set in a westerly 
direction. 

We who are placed midway between the Pole and 
the Equator, see a mixture of these two motions. Some 
stars seem to circle round and round, as all would do 
if we stood at the North Pole. Some stars seem to 
rise and set, as all would do if we stood at the Equator. 
So much for the seeming 
movements of the stars. 

But now, about their 
real movements. Are the 
stars fixed, or are they not? 
These seeming daily and 
yearly motions do not af- 
fect the question, being 
merely caused by our own 
motions. Trees and hedg- 
es may appear to move as 
we rush past them in a 
train, yet they are really 
fixed. 

During a long while, conspiration of orion 50,000 

. . . . ° , YEARS FROM NOW. 

after it was found out that 

the quick, daily movements of all the stars in com- 
pany were merely apparent, men believed that they 
really had no ''proper motions" — that is, no move- 
ments of their own. For century after century the 
constellations remain the same. Hundreds of years 
ago the seven chief stars of the Great Bear shone in 
company as they shine now. Who could suppose that 
each one of those seven stars is hurrying on its path 
through space with a speed exceeding far that of the 



BETELGEUSE..-0 

O"' \ 

V 9 


ALDEBARANq 


: \o>' 






fa 


O'' ;': 

PROOYON ! 


RIG EL 


&S/R/US 





112 STORY OF THE SUN, MOON, AND STARS. 

swiftest express-train? Yet so it is. Hundreds of 
years ago trie grand group of Orion, with belt and 
sword, gleamed brilliantly night by night as it gleams 
in these days ; and Cassiopeia had her W form, and 
Hercules and Draco and Andromeda were shaped as 
they are shaped still. Who would imagine that through 
those hundreds of years each star of these different 
constellations was hastening with more or less of speed 
along its heavenly road ? Yet so it is. 

Cases have been decisively ascertained of stars 
changing their places among the other stars by a slow 
and gradual motion. Three of the most conspicuous 
of them — Sirius, Arcturus, and Aldebaran — have been 
proved, by the comparison of modern with some an- 
cient observations, to have experienced a change of place 
to the southward, to the extent of more than the breadth 
of the moon in all the three. And during the period 
of accurate modern measurement, other instances have 
been ascertained of steady change of place by the 
effect of proper motion. 

But if the stars are thus rapidly moving in all di- 
rections, how is it that we do not see them move ? How 
is it that, night after night, year after year, century 
after century, even thousand years after thousand 
years, the shapes of the constellations remain un- 
altered? 

Suppose you and I were standing on the sea- 
shore together, watching the movements of scores of 
sea-craft, little boats and large boats, steamers, yachts, 
and ships. Suppose we stood through a full quarter 
of an hour looking on. Some might move, it is true, 
very slowly ; yet their movements in every case would 



our neighbors' movements. 113 

plainly be seen. There could be no possibility of 
mistaking the fact, or of supposing them to be 
"fixed." Just so we see the nearer planets move. 
Ivittle danger of our supposing them to be "fixed 
stars." 

In the matter of the stars themselves, we must 
carry our illustration further. Come with me up to 
the top of that lofty hill on the border of the sea, and 
let us look from the cliff. We see still the move- 
ments among boats and smacks, yachts and steamers, 
only the increased distance makes the movements 
seem slower. But our view is widened. Look on the 
far horizon and see three distant dots, which we know 
to be ships — one and two close together, and a third a 
little way off, making a small constellation of vessels. 
Watch them steadily for a quarter of an hour. You 
will detect no movement, no increased distance or 
nearness between any two of the three. The group 
remains unchanged. 

Are they really moving? Of course they are, more 
or less rapidly, probably with differing speed and in 
different directions. But at so great a distance, one 
quarter of an hour is not long enough for their mo- 
tions to become visible to the naked eye. If we 
could watch longer — say, for two or three hours — ah, 
that would make all the difference ! If only we could 
watch longer ! But the hundreds, and even thousands 
of years during which men have watched the stars, 
sink, at our vast distance, into no more than one quar- 
ter of an hour spent in watching the far-off ships from 
the high hilltop. The motions can not be detected. 
In ten thousand years you might see something. In 



114 STORY OF THE SUN, MOON, AND STARS. 

fifty thousand years you might see much. But four 
or five thousand years are not sufficient. 

One other mode there is, by means of which the 
movements of the ships on the horizon might be made 
plain. Suppose you had no more than the quarter of 
an hour to spare, but suppose you had at your com- 
mand a powerful telescope. Then you may practically 
bring the ships nearer, and by magnifying the small, 
slow, distant motions, you may make them, as it were, 
larger, quicker, more easy to see. 

Telescopes will do this for us, likewise, in the mat- 
ter of the stars. By means of telescopes, with the as- 
sistance of careful watching and of close calculation it 
has been found that the stars are really moving quickly, 
each one in his own pathway. The very speed of 
some of them has been measured. 

Arcturus is one of those stars, the motions of which 
are most plainly to be seen. In the course of about 
one thousand years he changes visibly his place in the 
sky by a space equal to the apparent diameter of the 
moon. The seeming movement of Arcturus in one 
thousand years is the same as the seeming width of 
the round moon that we see. 

But the actual speed with which Arcturus rushes 
through space is said to be no less than fifty-four 
miles each second, or not far from two hundred thou- 
sand miles an hour. That is nearly three times as 
fast as our own earth's motion round the sun. How 
enormous the distance must be which can shrink 
such speed to such seeming slowness ! 

Another beautiful star, Capella, is believed to travel 
at the rate of thirty miles each second. The speed 



our neighbors' movements. 115 

of Sirius is slower, being only fourteen miles a second. 
The Pole-star creeps along at the rate of only one 
mile and a half each second. 

So also with the rest of the stars. There seems 
good reason to believe that every star we see shining 
in the heavens, every star visible in powerful tele- 
scopes, is perpetually hastening onward. But hasten- 
ing whither? God knows ! We do not. 

In all probability not one of the tens of millions 
of stars which may be seen through telescopes is in 
repose. This is a matter of conjecture, of reasoning 
from analogy, and of reasoning also from the working 
of known laws. We know, as a consequence of direct 
observation, apart from the new spectroscopic method, 
that at least hundreds are upon the wing. We assume, 
as a matter of the greatest possible likelihood, that all 
the millions besides, which can not be actually seen 
to stir, are equally on the move. Knowing what we 
do know of the laws by which the universe of stars is 
governed, it seems to us an absolute impossibility that 
any single star, amid the whole vast host, can be or 
could be permanently at rest. 

If by any means a star were brought to repose — 
what then would happen? It would inevitably start 
off again, drawn by the attraction of other stars. 
From whatever direction the strongest pull came, the 
impulse would be given. Lengthened repose would be 
out of the question. And this, it seems to us, must 
be true, not of one star only, here or there, but of 
every star in the enormous host of radiant suns which 
make up the mighty Stellar System. 

Our forefathers, one thousand years ago, could not 



n6 story of the; sun, moon, and stars. 

measure the precise positions of individual stars, as 
astronomers now are able to do. They had no modern 
observatories, no telescopes, no spectroscopes, no pho- 
tographic appliances. These methods of observation 
we shall explain in another chapter. Their measure- 
ments at best were rough, their scientific knowledge 
was crude. Had we any such accurate observations 
handed down from one thousand years ago as are 
made in these days, we should no doubt see clearly 
many slight differences in the positions of many stars 
which are not now apparent. But even then we 
should see no changes sufficient in amount to affect 
the general outlines of the leading constellations. 

A star, which in the course of a century makes 
visible advance over a space in the sky equal to only 
a small portion of the breadth of the full moon, is 
looked upon as a fast voyager. One hundred times 
this degree of movement, if it took place in a con- 
siderable number of stars in our sky, would not in 
centuries very materially change the face of our mid- 
night heavens. 

And all motions which would in the remotest de- 
gree affect the shapes of constellations, must be side- 
way motions. Those line-of-sight motions, of which 
the spectroscope alone tells us, could never have been 
discovered by simple observation of the sky. Until 
the new method came to light we had no means 
whatever of perceiving such movements among the 
stars. 

Suppose you are looking at two men in the dis- 
tance, upon a wide, flat plain. One of the two is 
walking very slowly across your line of vision. The 



OUR NEIGHBORS* MOVEMENTS. I17 

second man is moving very slowly straight towards 
you. If you watch with care you may find out both 
the movements. The sideway walking will be ap- 
parent first and most easily, because, as the man 
moves, he has constantly a fresh part of the horizon 
behind him. But in time the advance of the second 
man towards you will also become apparent; for al- 
though he is seen still against precisely the same spot 
on the horizon, he slowly occupies a larger spot on 
the retina of your eye, — in other words, he seems to 
grow bigger. And that, as you know from long ex- 
perience, can only mean increasing nearness. 

If a star seemed to grow larger as it drew nearer, 
we should then be able to perceive that movement 
also. But no star in the sky ever does seem to grow 
any larger. Every star is to us but one point of light. 
It may be rushing towards us at an enormous rate of 
speed, yet still as a single point it remains, always at 
the same point in our sky. Therefore we have no 
chance of perceiving its movement ; or rather, we had 
no chance until the discovery of this new method. 
In fact, the very nearest known star is at so enor- 
mous a distance that, supposing it to be coming to- 
wards us at the rate of one hundred miles each 
second, it would still gain, in the course of a century, 
only one-fortieth part more of brightness than it has 
now. It would not increase at all in apparent size. 

When we leave behind us the thought of starry 
motions, as we faintly detect them at this great dis- 
tance, and picture to ourselves the actual far-off whirl 
of all those glorious suns, the effect upon the mind is 
overwhelming. Stars are found to be rushing hither 



Il8 STORY OF The sun, moon, and stars. 

and thither, at every degree of speed, in every imag- 
inable direction : stars to right, and stars to left ; stars 
towards us, and stars away from us ; stars alone, and 
stars in company, — all this, and more, deciphered out 
of the tiny gleam of quivering light, which streams 
through the vast abyss of space from each distant orb 
to earth. So real star-motions were known — first, 
through telescopic observation; secondly, through 
spectroscopic observation; and now, lastly, photog- 
raphy has stepped in, bringing with it much increase 
of exactitude. 

But if all the stars are moving, what of our sun? 
Our sun is a star. And our sun also is moving. He 
is pressing onward, in a wide sweep through space, 
bearing along with him his whole vast family — planets, 
satellites, comets, meteorites — round or towards some 
far distant center. For aught we know, every star in 
the heavens may have a like family traveling with him. 

In infinite space the stars are strewn in immense 
clusters, like archipelagoes of islands in the ocean 
of the heavens. To go from one star to another in 
the same archipelago light takes years; to pass from 
one archipelago to another it takes thousands of years. 
Each of these stars is a sun similar to ours, sur- 
rounded, doubtless, at least for the most part, by 
worlds gravitating in its light; each of these planets 
possesses, sooner or later, a natural history adapted to 
its constitution, and serves for many ages as the abode 
of a multitude of living beings of different species. 
Attempt to count the number of stars which people 
the universe, the number of living beings who are 
born and die in all these worlds, the pleasures and 



OUR NEIGHBORS' MOVEMENTS. 1 19 

pains, the smiles and tears, the virtues and vices ! Im- 
agination, stop thy flight! 

The sun is not one of the most quickly-moving 
stars. His rate of speed has not been found out with 
any certainty, but it is believed to be about four or 
five miles a second. 

And where are we going? This has been in 
part discovered. If you and I were driving through a 
forest of trees, we should see the trees on each side of 
us seeming to move backward, while behind they 
would close together, and in front they would open out. 

Astronomers — and first among them, William Her- 
schel — reasoned that if our Solar System were really 
in motion, we ought to be able to see these changes 
among the stars. And some such changes have be- 
come visible through careful watching — not so much 
those ahead and behind as those at the sides. 

It is not actually so simple a matter as looking at 
the trees in a forest, because the trees would be at rest, 
whereas each star has his own particular real motion, 
as well as his seeming change of place caused by our 
sun's motion. It is more like moving in a small 
steamer at sea, among hundreds of other craft, each 
of which is going on its own way, at the same time 
that all on either side seem to move backward because 
we are moving forward. 

So each movement had to be noted, and the real 
motions had to be separated from the seeming back- 
ward drift of stars to the right and left of the sun's 
pathway. The result of all this is that the sun, with 
his planets, is found to be hastening towards a certain 
far-off constellation named Hercules. 



120 STORY OF THE SUN, MOON, AND STARS. 

It is a strange and unexpected fact, but absolutely 
true, that each sun of space is carried along with a 
velocity so rapid that a cannon-ball represents rest in 
comparison ; it is at neither a hundred, nor three hun- 
dred, nor five hundred yards per second that the 
earth, the sun, Sirius, Vega, Arcturus, and all the 
systems of infinitude travel: it is at ten, twenty, 
thirty, a hundred thousand yards a second ; all run, fly, 
fall, roll, rush through the void — and still, seen as a 
whole, all seems in repose. 

The immense distance which isolates us from all 
the stars reduces them to the state of motionless lights 
apparently fixed on the vault of the firmament. All 
human eyes, since humanity freed its wings from the 
animal chrysalis, all minds since minds have been, 
have contemplated these distant stars lost in the ethe- 
real depths ; our ancestors of Central Asia, the Chal- 
deans of Babylon, the Egyptians of the Pyramids, the 
Argonauts of the Golden Fleece, the Hebrews sung by 
Job, the Greeks sung by Homer, the Romans sung by 
Virgil, — all these earthly eyes, for so long dull and 
closed, have been fixed, from age to age, on these eyes 
of the sky, always open, animated, and living. Ter- 
restrial generations, nations and their glories, thrones 
and altars have vanished : the sky of Homer is always 
there. Is it astonishing that the heavens were con- 
templated, loved, venerated, questioned, and admired, 
even before anything was known of their true beauties 
and their unfathomable grandeur ? 

Better than the spectacle of the sea, calm or agi- 
tated, grander than the spectacle of mountains adorned 
with forests or crowned with perpetual snow, the spec- 



OUR NEIGHBORS' MOVEMENTS. 121 

tacle of the sky attracts us, envelops us, speaks to us 
of the Infinite. " I have ascended into the heavens, 
which receive most of His light, and I have seen 
things which he who descends from on high knows 
not, neither can repeat," wrote Dante in the first canto 
of his poem on " Paradise." Let us, like him, rise to- 
wards the celestial heights, no longer on the trembling 
wings of faith, but on the stronger wings of science. 
What the stars would teach us is incomparably more 
beautiful, more marvelous, and more splendid than 
anything we can dream of. 

How do such contemplations enlarge and transfigure 
the vulgar idea which is generally entertained of the 
world! Should not the knowledge of these truths 
form the first basis of all instruction which aims at 
being serious ? Is it not strange to see the immense 
majority of human beings living and dying without 
suspecting these grandeurs, without thinking of learn- 
ing something of the magnificent reality which sur- 
rounds them? 

Where the sun and his planets will journey in fu- 
ture ages no living man can say. Indeed, though it 
is a question which does not lack interest to a thought- 
ful mind, yet there are numberless other questions 
about centuries near at hand which concern man far 
more nearly. The history of the Universe, and the 
history of this Earth of ours, must have advanced 
many broad stages before our sun and his attendant 
planets can have traveled so far that any change will 
be apparent -in the shape of the star-constellations 
which spangle our sky. 



CHAPTER XI. 

MORE ABOUT THE SOLAR SYSTEM. 

We have now reached a point where it ought not to 
be difficult for us to picture to ourselves, with something 
of vividness, the general outlines of the Solar System. 
Awhile ago this Solar System was a very simple 
matter in the eyes of astronomers. There was the 
great sun fixed in the center, with seven planets cir- 
cling round him — seven of course, it was said, since 
seven was the perfect number — and a few moons keep- 
ing pace with some of the planets, and an occasional 
comet, and a vast amount of black, empty space. But 
astronomers now begin to understand better the won- 
derful richness of the system as a whole; the immense 
variety of the bodies contained in it; the perpetual 
rush and stir and whirl of life in every part. Cer- 
tainly there is no such thing as dull stagnation 
throughout the family. 

First, we have the great, blazing, central sun ; not 
a sun at rest, as regards the stars, but practically at 
rest as regards his own system, of which he is always 
head and center. Then come the four smaller plan- 
ets, rapidly whirling round him, all journeying in the 
same direction, and all having their oval pathways ly- 
ing on nearly the same flat plane in space. Then the 
broad belt of busy little planetoids. Then the four 
giant planets, — Jupiter nearly five times as far as our 
earth from the sun ; Saturn nearly twice as far as Ju- 

122 



MORE ABOUT THE SOLAR SYSTEM. 



123 



piter; Uranus nearly twice as far as Saturn; Neptune 

as far from Uranus as Uranus from Saturn, — all keeping 

on very nearly the same level as the four inner planets. 

And between and about these principal members of 




POSITION OF PLANETS INFERIOR TO JUPITER— SHOWING THE 
ZONE OF THE ASTEROIDS. 



the system, with their accompanying moons, we have 
thousands of comets flashing hither and thither, with 
long, radiant trains ; and myriads of meteorites, gathered 
often into dense, vast herds or families, but also scat- 
tered thickly throughout every part of the system, 



124 STORY OF TH£ SUN, MOON, AND STARS. 

each tiny ball reflecting the sun's rays with its little 
glimmer of light. 

Broad reaches of black and empty space ! Where 
are they? Perhaps nowhere. We are very apt, in 
our ignorance, to imagine that where we see nothing, 
there must of necessity be nothing. But, for aught 
we know, the whole Solar System, not to speak of 
sky-depths lying beyond, may be bright with reflect- 
ing bodies great and small, from the mighty Jupiter 
down to the fine diamond-dust of countless meteorites. 
In this earth of ours we find no emptiness. Closer 
and closer examination with the microscope only 
shows tinier and yet tinier wonders of form and life, 
each perfect in finish. Not of form only, but of life. 
How about that matter as regards the Solar System? Is 
our little world the one only spot in God's great uni- 
verse which teems with life? Are all other worlds 
mere barren, empty wastes? Surely not. We may 
safely conclude that life of one kind or another has 
been, is, or will be, upon our brother and sister 
worlds. 

The same reasoning may be used for the distant 
stars — those millions of suns lying beyond reach of 
man's unassisted eyes. Are they formed in vain? 
Do their beams pour uselessly into space, carrying 
light, warmth, and life-giving power to nothing? 
Surely around many of them, as around our sun, 
must journey worlds ; and not only worlds, but worlds 
containing life. 

We shall have to speak of this matter again as we 
go on. Whether men and women like ourselves could 
live on the other planets is another question. In some 



MORE ABOUT THE SOLAR SYSTEM. 1 25 

cases it looks doubtful, in some it would seem to be 
impossible. But the endless variety of life on this 
earth — life on land, life in the air, life in water, life 
underground, life in tropical heat, life in arctic cold — 
forbids us in anywise to be positive as to what may or 
may not be. 

If no animals that we know could exist there, ani- 
mals that we do not know might be found instead. 
Any one of the planets may, and very likely does, 
abound with life. Nay, the very meteorites them- 
selves, before they catch fire and burn in our air, may 
be the homes of tiny animalcula, altogether different 
from anything we see on earth. We can not fancy 
life without air, but neither could we fancy life in 
water, if we had not seen and known it to be possible. 

I have spoken of the probable brightness of the 
Solar System as a whole. We are so apt to think of 
things merely as we see them with our short sight, 
that it is well sometimes to try to realize them as 
they actually are. Picture to yourself the great cen- 
tral sun pouring out in every direction his burning 
rays of light. A goodly abundance of them fall on 
our earth, yet the whole amount of light and heat re- 
ceived over the whole surface of this world is only the 
two-thousand-millionth part of the enormous amount 
which he lavishly pours into space. How much of 
that whole is wasted? None, though God gives his 
gifts with a kingly profusion which knows no bounds. 
Each ray has its own work to do. Millions of rays 
are needed for the lighting and nourishing and warm- 
ing of our companion-planets, while others are caught 
up by passing comets, and myriads flash upon swift, 



126 STORY OF THE SUN, MOON, AND STARS. 

tiny meteorites. Of the rays not so nsed, many pass 
onwards into the vast depths beyond onr system, and 
dwindle down into dim, starlike shining till they reach 
the far-off brother-stars of our sun. 

Have they work to do there? We can not tell. 
We do not know how far the sun's influence reaches. 
As head and center, he reigns only in his own sys- 
tem. As a star among stars, a peer among his equals, 
he may, for aught we can tell, have other work to do. 

In an early chapter, mention was made of the 
earth's three motions, two only being explained. 
First, she spins ceaselessly upon her axis. So does 
the sun, and so do the planets. Secondly, she travels 
ceaselessly round and round the sun in her fixed orbit. 
So does each one of the planets. Thirdly, she jour- 
neys ceaselessly onward through space with the sun. 
So also do the rest of the planets. These last two 
movements, thought of together, make the earths 
pathway rather perplexing at first sight. We talk of 
her orbit being an ellipse or oval; but how can it be 
an ellipse, if she is always advancing in one direction? 

The truth is, the earth's orbit is and is not an 
ellipse. As regards her yearly journey round the sun, 
roughly speaking, we may call it an ellipse. As re- 
gards her movement in space, it certainly is not an 
ellipse. 

Think of the Solar System, with the orbits of all 
the planets, as lying nearly flat — in the manner that 
hoops might be laid upon a table, one within another. 
The asteroids, comets, and meteorites do not keep to 
the same level ; but their light weight makes the mat- 
ter of small importance. 



MOR£ ABOUT THE SOLAR SYSTEM. 12/ 

Having imagined the sun thus in the center of a 
large table — a small ball, with several tiny tails trav- 
eling round him on the table at different distances — 
suppose the sun to rise slowly upwards, not directly 
up, but in a sharp slant, the whole body of planets 
continuing to travel round, and at the same time rising 
steadily with him. 

By carefully considering this double movement, 
you will see that the real motion of the earth — as 
also of each of the planets — is not a going round on 
a flat surface to the same point from which she started, 
but is a corkscrew-like winding round and round up- 
wards through space. Yet as regards the central sun, 
the shape of the orbit comes very near being an el- 
lipse, if calculated simply by the earth's distance from 
him at each point in turn of her pathway through 
the year. 

An illustration may help to explain this. On the 
deck of a moving vessel, you see a little boy walking 
steadily round and round the mast. Now is that 
child moving in a circle, or is he not? Yes, he is. 
No, he is not. He walks in a circle as regards the 
position of the mast, which remains always the center 
of his pathway. But his movement in space is never 
a circle, since he constantly advances, and does not 
once return to his starting-point. You see how the 
two facts are possible side by side. Being carried 
forward by the ship, with no effort of his own, the 
forward motion does not interfere with the circling 
motion. Each is performed independently of the 
other. 

It is the same with the earth and the planets. 



128 STORY OF THE SUN, MOON, AND STARS. 

The sun, by force of his mighty attraction, bears 
them along wherever he goes — no exertion on their 
part, so to speak, being needed. That motion does 
not in the least interfere with their steady circling 
round the sun. 

Just as — to use another illustration — the earth, 
turning on her axis, bears through space a man stand- 
ing on the Equator at the rate of one thousand miles 
an hour. But this uniform movement, unfelt by him- 
self, does not prevent his walking backwards, or for- 
wards, or in circles, as much as he will. 

So, also, a bird in the air is unconsciously borne 
along with the atmosphere, yet his freedom to wheel 
in circles for any length of time is untouched. 

A few words about the orbits of the planets. I 
have more than once remarked that these pathways 
are, in shape, not circles, but ellipses. A circle is a 
line drawn in the shape of a ring, every part of which 
is at exactly the same distance from the center-point 
or focus. But an ellipse, instead of being, like a circle, 
perfectly round, is oval in shape ; and instead of hav- 
ing only one focus, it has two foci, neither being ex- 
actly in the center. Foci is the plural word for focus. 
If an ellipse is only slightly oval — or slightly elliptical 
— the two foci are near together. The more oval or 
eccentric the ellipse, the farther apart are the tv/o foci. 

You may draw a circle in this manner. Lay a 
sheet of white paper on a board, and fix a nail through 
the paper into the board. Then pass a loop of thread 
— say an inch or an inch and a half in length — round 
the nail, and also round a pencil, which you hold 
Trace a line with the pencil, keeping the loop tight, 



MORE ABOUT THE SOLAR SYSTEM. 1 29 

so that the distance of your line from the nail will be 
always equal, and when it joins you have a circle. 
The nail in the center is the focus of the circle. 

To draw an ellipse, you must fix two nails. Let 
them be about half an inch apart; pass a loop over 
both of them, and again placing a pencil point within 
the loop, again trace a line carefully all round, keep- 
ing the thread drawn tight. This time an oval instead 
of a circle will appear. By putting the nails nearer 
together or farther apart, you may vary as you will 
the shape of the ellipse-. 

In the orbits of the earth and the planets, all of 
which are ellipses in shape, the sun is not placed in 
the exact center, but in one of the two foci, the sec- 
ond being empty. So at one time of the year the 
planet is nearer to the sun than at another time. Our 
earth is no less than three millions of miles nearer in 
winter than she is in summer — speaking of the winter 
and summer of the northern hemisphere. Three mill- 
ions of miles is so tiny a piece out of ninety-three 
millions of miles, that it makes little or' no difference 
in our feelings of heat or cold. 

The orbits of the comets are ellipses also, but ellip- 
ses often so enormously lengthened out, that the two 
foci are almost — if one may so speak — at the two ends 
of the oval. To draw a good comet orbit, you must 
fix the two nails on your paper some five or six 
inches apart, with a loop of thread just large enough to 
slip over them both, and to allow the pencil to pass 
round them. When your ellipse is drawn, you must 
picture the sun in the place of one of the two nails, 
and you will see how, in their pathways, the comets 
9 



130 story of th£ Sun, moon, and stars. 

at one time pass very near the sun, and at another 
time travel very far away from him. 




COMPARATIVE SIZE OF THE PLANETARY WORLDS. 

It is generally found in families, not only that the 
parent or head of the family has great influence over 
all the members, but that each member has influence 



more: about the solar system. 131 

over each other member. Brother influences brother, 
and sister influences sister. 

This, too, we find in the Solar System. Not only 
does the sun, by his powerful attraction, bind the 
whole family together, but each member of the fam- 
ily attracts each other member. True, the force of 
the sun's attraction is overpowering in amount com- 
pared with others. The sun attracts the planets, and 
the planets attract the sun ; but their feeble pulling is 
quite lost in the display of his tremendous strength. 

Among themselves we see the power more plainly. 
The earth attracts the moon, keeping her in constant 
close attendance; and the moon attracts the earth, caus- 
ing a slight movement on her part, and also causing the 
tides of the sea. Each planet has more or less power 
to hinder or help forward his nearest brother-planet. 
For instance, when Jupiter on his orbit draws near 
the slower Saturn on his orbit, Saturn's attraction 
pulls him on, and makes him move faster than usual; 
but as soon as he gets ahead of Saturn then the same 
attraction pulls him back, and makes him go more 
slowly than usual. Jupiter has the same influence 
over Saturn ; and so also have Saturn and Uranus over 
one another, or Uranus and Neptune. 

In early days astronomers were often greatly puz- 
zled by these quickened and slackened movements, 
which could not be explained. Now the " perturba- 
tions" of the planets, as they are called, are under- 
stood and allowed for in all calculations. Indeed, it 
is by means of this very attraction that Neptune was 
discovered, and the planets have actually been weighed. 
What a wonderful difference we find in this picture 



132 STORY OF THE SUN, MOON, AND STARS. 

of the Solar System, as we now know it to be, from 
the old-world notion of our earth as the center of the 
universe ! 

When we think of all the planets, and of the mag- 
nificent sun; when we pass onward in imagination 
through space, and find our sun himself merely one 
twinkling star amid the myriads of twinkling stars 
scattered broadcast through the heavens, while plan- 
ets and comets have sunk to nothing in the far dis- 
tance, — then indeed we begin to realize the unuttera- 
ble might of God's power! Why, our earth and all 
that it contains may be regarded as but one grain of 
dust in the wide universe. 



CHAPTER XII. 

MORE ABOUT THE SUN. 

Not among the least of the wondrous things of 
creation are the tremendous disturbances taking place 
upon the surface of the sun — that raging, roaring sea 
of name. 

A good many explanations have been from time to 
time offered as to the dark spots seen to move across 
the face of the sun. Some one or more of these ex- 
planations may be true; but we know little about the 
matter. A sun-spot does not commonly consist of 
merely one black patch. There is the dark center, 
called the umbra — plural, umbrcz. There is the gray- 
ish part surrounding the umbra, called the penumbra. 
Also, in the center of the umbra there is sometimes 
observable an intensely black spot, called the nucleus. 
Sometimes a spot is made up of nucleus and umbra 
alone, without any penumbra. Sometimes it is made 
of penumbra alone, without any umbra. Sometimes 
in one spot there are several umbrae, with the gray 
penumbra round the whole, and gray bridges dividing 
the umbrae. 

The enormous size of these spots has been already 
described in an earlier chapter. Fifty thousand to 
one hundred thousand miles across is nothing unusual. 
In the year 1839 a spot was seen which measured no 
less than one hundred and eighty-six thousand miles 
in diameter. 

133 



134 STORY OF THE SUN, MOON, AND STARS. 

One explanation proposed was, that trie sun might 
be a cool body, covered over with different envelopes 
or dense layers of cloudy form, one above another. 
The inside envelope — or, as some say, the inside at- 
mosphere — would then be thick and dull-colored, 
protecting the solid globe within and reflecting light, 
but having none of its own. The next envelope 
would be one mass of raging, burning gases — the 
photosphere, in fact. The outer envelope would be a 
transparent, surrounding atmosphere, lighted up by 
the sea of fire within. A sun-spot would then consist 
of the tearing open of one or more of these envelopes, 
so as to give glimpses of the gray, inner atmosphere, 
or even of the dark, cool globe at the center. 

There may be some truth in this explanation ; but 
the notion of a cool and dark body within is now 
pretty well given up. The apparent blackness of a 
spot-nucleus does not prove actual blackness or ab- 
sence of heat. A piece of white-hot iron, held up 
against the sun, looks black; and it may be merely 
the contrast of the glowing photosphere which makes 
the nucleus seem so dark. It is even believed that 
the blackest parts may be the most intensely hot 
of all. 

Another proposed explanation was of dark clouds 
floating in the sun's atmosphere. There, again, are 
found difficulties, particularly in the fact that, as the 
spots move across the sun, the changes which regu- 
larly take place in their appearance make it pretty 
clear that their shape is not flat, but hollow and cave- 
like. The changes here spoken of are seeming 
changes of shape, caused by change of position. 



MORE ABOUT THE SUN. 



135 



There are also real changes constantly taking place. 
Although the spots often keep their general outlines 
long enough to be watched across the face of the sun, 
and even to be known again after spending nearly a 




A TYPICAL SUN-SPOT. 

fortnight hidden on the other side, still they are far 
from being fixed in form. 

The alterations are at times not only very great, 
but very rapid. Sometimes in a single hour of watch- 
ing, an astronomer can see marked movement going 



136 STORY OF THE SUN, MOON, AND STARS. 

on — as you or I might in an hour observe movements 
slowly taking place in a high layer of clouds. For 
movement to show at all in one hour, at so immense 
a distance, proves that the actual rate of motion must 
be very great. 

The first great fact which was got from the study 
of these spots was this, that this great sun is very 
much like our own earth, in so far as it rotates on an 
axis in exactly the same way that our earth does. Not 
only do the spots change their position on the face of 
the sun, in consequence of the sun's rotation on its 
axis, but they change very much from day to day, and 
even from hour to hour; so that we have evidence not 
only that the sun is rotating like our earth, but that 
the atmosphere of the sun is subjected to most tre- 
mendous storms — storms so tremendous, in fact, that 
the fiercest cyclones on our own earth are not for one 
moment to be compared with them. The fact that 
the spots do really move with the sun, and are really 
indentations, saucer-like hollows, in the photosphere, 
is shown by the appearance, which is always presented 
by a spot when it is near the edge of the sun. You 
know if you take a dinner-plate, and look it full in 
the face, it is round ; but if you look at it edgeways, 
it is not round. Take two different views of the same 
spot : In one, you look the sun-spot straight in the face, 
and you see into it and can learn all about it ; but in 
the other, when it has nearly gone round the corner, 
and is disappearing on the sun's edge, you see it in 
the same way that you would see a plate looked at 
edgeways. 

These sun-cyclones must indeed be of terrific force 



MORE ABOUT THE SUN. 137 

and extent, compared with anything we see on earth. 
It was calculated that the speed of movement per- 
ceived in one spot was about three hundred and sixty- 
three miles each second. 

And still all this is nothing, or almost nothing, in 
comparison with the real power of the sun! The 
liquid state of the ocean ; the gaseous state of the at- 
mosphere; the currents of the sea; the raising of the 
clouds, the rains, storms, streams, rivers; the calorific 
value of all the forests of the globe and all the coal- 
mines of the earth; the motion of all living beings; 
the heat of all humanity; the stored-up power in 
all human muscles, in all the manufactories, in all 
the guns, — all that is almost nothing compared 
with that of which the sun is capable. Do we 
think that we have measured the solar power 
by enumerating the effects which it produces on 
the earth? Error! profound, tremendous, foolish 
error ! This would be to believe still that this star has 
been created on purpose to illuminate terrestrial hu- 
manity. In reality, what an infinitesimal fraction of 
the sun's total radiation the earth receives and utilizes! 
In order to appreciate it, let us consider the distance 
of ninety-three millions of miles which separates us 
from the central star, and at this distance let us see 
what effect our little globe produces, what heat it in- 
tercepts. Let us imagine an immense sphere traced at 
this distance from the sun, and entirely surrounding it. 
Well, on this gigantic sphere, the spot intercepted by 
our little earth is only equivalent to the fraction 
2,138,000,000 ; that is to say, that the dazzling solar hearth 
radiates all round it through immensity a quantity of 



138 STORY OF THE SUN, MOON, AND STARS. 

light and heat two thousand one hundred and thirty- 
eight million times more than that which we receive, 
and of which we have just now estimated the stupen- 
dous effects. The earth only stops in its passage the 
two thousand millionth part of the total radiation. 

Sometimes the storms or outbursts come in the 
shape of a bright spot instead of a dark one. 




A SOI,AR ERUPTION. 



Two astronomers were one day watching the sun 
from two different observatories, when they saw such 
an event take place. An intense and dazzling spot of 
light burst out upon the surface of the sun — so in- 
tense, so dazzling, as to stand quite apart from the 
radiant photosphere. To one astronomer it looked 
like a single spot, while the other saw two spots close 
together. In about a minute the light grew more 
dim, and in five minutes all was over. But in those 
five minutes the spot or spots had traveled a distance 
of thirty-five thousand miles. 



MORE ABOUT THK SUN. 139 

It was a very remarkable thing that the magnets 
on earth — those delicate little needles which point so 
steadily yet perseveringly towards the North Pole — 
seemed to be strongly agitated by the distant solar 
outburst. This brings us to another interesting fact. 

The spots on the sun are not always the same in 
number. Sometimes they are many, sometimes they 
are few. Long and close watching has made it clear 
that they pass through a regular order of changes: 
some years of many spots being followed by other 
years of less and less spots; then some years of very 
few spots being followed by other years of more and 
more spots, — decrease and increase being seemingly 
regular and alternate. < 

This turn or cycle of changes — from more to less, 
and then from less to more again — is found to run its 
course about once in every eleven years, with some 
variations. 

Now, it has long been known that the magnetic- 
needle goes through curious variations. Though we 
speak of it as pointing always north, yet it does not 
always so point exactly. Every day the needle is 
found to make certain tiny, delicate motions, as if 
faintly struggling to follow the daily movements of 
the sun — just a little towards the east, or just a little 
towards the west. These tiny motions, having been 
long watched and measured, were found to go through 
a regular course of changes — some years more, and 
some years less, waxing and waning by turns. It was 
discovered that the course of changes from more to 
less, and from less to more again, took place in about 
eleven years. 



140 STORY OF THE) SUN, MOON, AND STARS. 

These two things, you see, were quite independent 
of one another. Those who watched the sun-spots 
were not thinking of the magnets, and those who 
watched the magnets were not thinking of the sun- 
spots. But somebody did at last happen to think of 
both together. He was laughed at, yet he took the 
trouble carefully to compare the two. And, strange 
to say, he found that these two periods in the main 
agreed — the eleven years of alternate changes in the 
number of sun-spots, and the eleven years of alternate 
changes in the movements of the magnetic-needle. 
When the spots are most, the needle moves most. 
When the spots are least, the needle moves least. 
So much we know. But to explain the why and the 
wherefore is beyond our power. 

This study of the magnetism of our wandering 
planet is very interesting, and one which is still very 
little known. Here is a weak needle, a slip of mag- 
netic iron, which, with its restless and agitated finger, 
incessantly seeks a region near the north. Carry this 
needle in a balloon up to the higher aerial regions, where 
human life begins to be extinguished ; shut it up in a 
tomb closely separated from the light of day ; take it down 
into the pit of a mine, to more than a thousand yards in 
depth, — and incessantly, day and night, without fatigue 
and without rest, it watches, trembles, throbs, seeks 
the point which attracts it across the sky, through the 
earth, and through the night. Now — and here is a 
coincidence truly filled with notes of interrogation — ■ 
the years when the oscillation of this innocent little 
steel wire is strongest are the years when there are 
more spots, more eruptions, more tempests in the sun ; 



MORH ABOUT THE SUN. 141 

and the years when its daily fluctuations are weakest 
are those when we see in the day-star neither spots, 
eruptions, nor storms. Does there exist, then, a mag- 
netic bond between the immense solar globe and our 
wandering abode? Is the sun magnetic? But the 
magnetic currents disappear at the temperature of red- 
hot iron, and the incandescent focus of light is at a 
temperature incomparably higher still. Is it an elec- 
trical influx which is transmitted from the sun to the 
earth across a space of ninety-three millions of miles? 
On September 1, 1859, two astronomers — Carring- 
ton and Hodgson— were observing the sun, independ- 
ently of each other; the first on a screen which 
received the image ; the second directly through a tele- 
scope, — when, in a moment, a dazzling flash blazed out 
in the midst of a group of spots. This light sparkled 
for five minutes above the spots without modifying 
their form, as if it were completely independent, and 
yet it must have been the effect of a terrible confla- 
gration occurring in the solar atmosphere. Each ob- 
server ascertained the fact separately, and was for an 
instant dazzled. Now, here is a surprising coincidence : 
at the very moment when the sun appeared inflamed 
in this region the magnetic instruments of the Kew 
Observatory, near London, where they were observ- 
ing, manifested a strange agitation; the magnetic 
needle jumped for more than an hour as if infatuated. 
Moreover, a part of the world was on that day and 
the following one enveloped in the fires of an aurora 
borealis, in Europe as well as in America. It was 
seen almost everywhere, — at Rome, at Calcutta, in 
Cuba, in Australia, and in South America. Violent 



142 STORY OF THE SUN, MOON, AND STARS. 

magnetic perturbations were manifested, and at sev- 
eral points the telegraph-lines ceased to act. Why 
should these two curious events not be associated with 
each other? A similar coincidence was observed on 
August 3, 1872, by Professor Charles A. Young, of 
Princeton, N. J. : a paroxysm in the solar chromo- 
sphere, magnetic disturbances everywhere. 

There is a very singular appearance seen upon the 
sun which must not be passed over without mention. 
Some astronomers speak of the whole surface as being 
mottled all over with a curious rough look when exam- 
ined through a powerful telescope. This "mottling" 
is described by various observers in various ways. 
One speaks of "luminous spots shaped like rice- 
grains." Another, of "luminous spots resembling 
strokes made with a camePs-hair pencil." Another, 
of "luminous objects or granules." Others, of "mul- 
titudes of leaves," "nodules," "crystalline shapes," 
"leaves or scales, crossing one another in all direc- 
tions, like what are called spills in the game of spilli- 
kens." They have also been pictured as "certain 
luminous objects of an exceedingly definite shape and 
general uniformity of size, whose form is that of the 
oblong leaves of a willow- tree." These cover the whole 
disk of the sun, excepting the space occupied by the 
spots, in countless millions, and lie crossing each other 
in every imaginable direction. 

In size they are said to be about one thousand miles 
long, by two or three hundred broad, but they vary a 
good deal. Where there is a spot, the willow-leaves 
at its edge are said to point pretty regularly towards 
the center. Whether they are, as they seem to be, 



MORE ABOUT THE SUN. 



143 



solid in form ; whether they are, as some suppose, the 
chief source of the sun's light and heat ; whether they 
lie on his surface or float in his atmosphere; what is 
their real nature, and what is their real use, — about 
these questions we are at present quite in the dark. 

We have next to 
think a little more 
about the edge or 
limb of the sun, 
and the stormy 
flames and out- 
burst there seen. 
Until quite lately 
the only time for 
observing such ap- 
pearances was dur- 
ing a total eclipse 
of the sun. Lately, 
by means of the 
new instrument 
called the " spectro- 
scope," it has been 
found possible to 
take observations when no eclipse is going on. 

A few words of explanation as to eclipses of the 
sun seem needful, before going further. An eclipse 
of the sun is caused simply by the round body of the 
moon passing exactly between the sun and the earth, 
so as to hide the sun from us. 

Let there be a candle on the table, while you stand 
near. The rays of light from the candle fall upon 
your face. Now move slowly, to and fro, a round ball 




SUN-FLAMES, MAY 3, 1892. 



144 story of the: sun, moon, and stars. 

between you and the candle. So long as it is not pre- 
cisely in the line between — so long as it is a little 
higher, or a little lower, or a little to one side — then 
yon can still see the flame. Once let the ball come 
just between the light and your eyes, and you see it no 
more. In other words the candle-flame is eclipsed — 
hidden, veiled, cut off — by the ball. 

It may seem curious at first sight that the moon, 
which is very small compared with the sun, should 
have power to cover the sun. But remember the dif- 
ference of the distance. The sun is very far, and the 
moon is very near. Any small object very near will 
easily hide from your sight a large object at a con- 
siderable distance. You may hold up a shilling-piece 
at arm's length, and make it cover from sight a man, 
or even a house, if the latter be far enough away. 
The sun at a distance of ninety-three millions of miles, 
and the moon at a distance of two hundred and forty 
thousand miles, have to our vision the same seeming 
size. So, when the moon glides between, her round 
face just about covers the sun's round face. 

If the moon were traveling exactly in the same 
plane as the plane of the earth's orbit, an eclipse would 
be a very common affair indeed. But the plane of the 
moon's orbit being not quite the same as the plane of 
the earth's orbit, she passes sometimes a little above, 
and sometimes a little below, the exact spot where 
she would hide the sun's rays from us. Now and 
then, at certain intervals, she goes just between. And 
so well is the moon's path in the heavens understood 
that astronomers can tell us, long years beforehand, 
the day and the hour an eclipse will take place. 



MORE ABOUT THE SUN. 145 

An eclipse of the sun is sometimes partial, some- 
times total, sometimes annular. In a partial eclipse, 
the moon does indeed pass between, but only so as to 
hide from us part of the sun. She is a little too low, 
or a little too high, to cover his face. In a total 
eclipse, the moon covers the sun completely, so that 
for a few minutes the bright photosphere seems blot- 
ted out from the heavens, a black round body, sur- 
rounded by light, taking its place. In an annular 
eclipse, the moon in like manner crosses the sun, but 
does not succeed in covering him entirely, a rim of 
bright photosphere showing round the black moon. 
For in an annular eclipse, the moon, being a little 
farther away from the earth than at the time of a 
total eclipse, has too small a disk quite to hide the 
sun's disk. 

The blackness of the moon during an eclipse is 
caused by the fact that her bright side is turned to- 
wards the sun, and her dark side toward us. An 
eclipse of the sun can take place only at new moon, 
never at full moon. At her full, the moon is outside 
the earth's orbit, away from the sun, and can not by 
any possibility pass between. 

Eclipses, like comets, have always been inter- 
preted as the indication of inevitable calamities. 
Human vanity sees the finger of God making signs 
to us on the least pretext, as if we were the end and 
aim of universal creation. Let us mention, for ex- 
ample, what passed even in France, with reference to 
the announcement of an eclipse of the sun, on August 
21, 1560. For one, it presaged a great overthrow of 
States and the ruin of Rome; for another, it implied 



I46 STORY OF THK SUN, MOON, AND STARS. 

another universal deluge; for a third, nothing less 
would result than a conflagration of the globe ; finally, 
for the less excited, it would infect the air. The be- 
lief in these terrible effects was so general that, by 
the express order of the doctors, a multitude of fright- 
ened people shut themselves up in very close cellars, 
well heated and perfumed, in order to shelter them- 
selves from these evil influences. Petit relates that 
the decisive moment approached, that the consterna- 
tion was at its height, and that a parish priest of the 
country, being no longer able to confess his parish- 
ioners, who believed their last hour had come, was 
obliged to tell them in a sermon " not to be so much 
hurried, seeing that, on account of the wealth of the 
penitents, the eclipse had been postponed for a fort- 
night." These good parishioners found no more diffi- 
culty in believing in the postponement of the eclipse 
than they had in believing in its unlucky influence. 

History relates a crowd of memorable acts on which 
eclipses have had the greatest influence. Alexander, 
before the battle of Arbela, expected to see his army 
routed by the appearance of a phenomenon of this 
kind. The death of the Athenian general Nicias and 
the ruin of his army in Sicily, with which the decline 
of the Athenians commenced, had for their cause an 
eclipse of the moon. We know how Christopher Co- 
lumbus, with his little army, threatened with death by 
famine at Jamaica, found means of procuring provis- 
ions from the natives by depriving them in the evening 
of the light of the moon. The eclipse had scarcely 
commenced when they supplied him with food. This 
was the eclipse of March 1, 1504. We need not relate 



MORE ABOUT THE SUN. 147 

other facts of this nature, in which history abounds, 
and which are known to every one. 

Eclipses no longer cause terror to any one, since we 
know that they are a natural and inevitable conse- 
quence of the combined motions of the three great 
celestial bodies — the sun, the earth, and the moon; 
especially since we know that these motions are reg- 
ular and permanent, and that we can predict, by means 
of calculation, the eclipses which will be produced in 
the future as well as recognize those which have oc- 
curred in the past. 

The following description of the total eclipse of 
i860 will be found interesting. Mr. Lowe, who ob- 
served it at Santander, Spain, thus writes : 

" Before totality commenced, the colors in the sky 
and on the hills were magnificent beyond all descrip- 
tion. The clear sky in the north assumed a deep 
indigo color, while in the west the horizon was first 
black like night. In the east the clear sky was very 
pale blue, with orange and red, like sunrise. On the 
shadow creeping across, the deep blue in the north 
changed, like magic, to pale, sunrise tints of orange 
and red, while the sunrise appearance in the east had 
changed to indigo. The darkness was great; the 
countenances of men were of a livid pink. The 
Spaniards lay down, and their children screamed with 
fear; fowls hastened to roost, ducks clustered to- 
gether, pigeons dashed against the houses; flowers 
closed; many butterflies flew as if drunk, and at last 
disappeared. The air became very humid, so much 
so that the grass felt to one of the observers as if re- 
cently rained upon." 



CHAPTER XIII. 

YET MORE ABOUT THE SUN. 

Having seen something of storms taking place on 
the sun's photosphere, we must next give our atten- 
tion to storms taking place at his edge. But it should 
be remembered that the said edge, far from being a 
mere rim to a flat surface, is a kind of horizon-line— 
is, in fact, just that part of the photosphere which is 
passing out of or coming under our sight. The sur- 
face there is, in kind, the same as the surface of the 
broad disk facing us. In watching outbursts at the 
edge of the sun, we have a side view instead of a 
bird's-eye view. 

In the year 187 1, Professor Charles A. Young, of 
Princeton, was looking at a large hydrogen cloud on 
the edge of the sun. When I speak of a "cloud," it 
must not be supposed that anything like a damp, 
foggy, earthly cloud is meant. This solar cloud was a 
huge mass of red-hot gas, about one hundred thou- 
sand miles long, rising to a height of fifty thousand 
miles from the sun's surface, and appearing to rest 
on glowing pillars of fire. 

The professor, while watching, was called away for 
half an hour. He came back, expecting to find things 
much as he had left them. Instead of this, a start- 
ling change had taken place. The whole mass of 
glowing fire seemed to have been actually " blown to 
shreds" by some tremendous outburst from below. 

148 



YET MORE ABOUT THE SUN. 1 49 

In place of the motionless cloud were masses of scat- 
tered fire, each from about four thousand to fourteen 
thousand miles long, and a thousand miles wide. 

As the professor gazed, these "bits" of broken 
cloud rose rapidly upwards, away from the surface of 
the sun. When I say "rapidly," I mean that the real 
movement, which the professor could calculate, was 
rapid. The seeming movements were of course slow, 
and over a small space. The actual motions were not 
tardy, for in ten minutes these huge, fiery cloud-pieces 
rushed upwards to a height of two hundred thousand 
miles from the edge of the sun, moving at a rate of at 
least one hundred and sixty-seven miles each second. 
Gradually they faded away. 

But what caused this sudden change? Just before 
the professor was interrupted, he had noticed a curi- 
ous little brilliant lump — a sort of suspicious thunder- 
cloud appearance — below the quiet, bright cloud. And 
after this tremendous shattering, the little bright lump 
rose upwards into a huge mass of rolling flame, reach- 
ing like a pyramid to a height of fifty thousand miles. 
In the course of a few minutes these enormous flames 
could be seen to move and bend, and to curl over their 
gigantic tips. But they did not last long. At half- 
past twelve the professor had been called away; by 
half-past two the rolling flames completely vanished. 

Now, whatever may be the full explanation of this 
sight, there is no doubt that on that day was observed 
from earth a tremendous outburst, compared with 
which our mightiest volcanoes are like the sputtering 
of a farthing dip beside a roaring furnace. The aw- 
ful force and greatness of such a solar eruption are 



150 STORY OF THE SUN, MOON, AND STARS. 

more than we can possibly picture to ourselves. At 
our distance we may catch a faint glimpse of what is 
going on, and calculate speed of movement. But 
vividly to realize the actual terrific grandeur of what 
took place is past our power. 

Possibly this was much the same kind of outburst 
as that seen by the two English astronomers; only 
theirs was a bird's-eye view, as it were, looking down 
on the top of the sight, while the professor had a side- 
view, certainly much the best for observation. 

It does not follow from what he saw that the erup- 
tion must have taken place exactly at the "edge" of 
the sun. Probably it happened near the edge. All 
he could say, was that the flames rose fifty thousand 
miles, and the pieces of cloud were carried two hun- 
dred thousand miles, away from the edge. The erup- 
tion may have begun on the other side of the sun, at 
any distance from the horizon-edge where it first be- 
came visible to earthly eyes. 

Also, while the professor found that the shattered 
cloudlets moved at a rate of about one hundred and 
sixty-seven miles each second, it is calculated that the 
first fearful outburst must have caused movement, 
near the surface of the sun, at a rate of at least three 
hundred miles each second. Probably the hydrogen 
cloud was borne upwards along with a vast mass of 
fragments flung out from the sun. We are here upon 
doubtful ground; but this tremendous power of erup- 
tion in the sun, and of driving matter out of and away 
from his surface, should not be forgotten. 

Though such a sun-storm as that just described is 
not often to be seen, yet there are at all times certain 



YET MORE ABOUT THE SUN. 151 

strange red prominences, or glowing flames, rising up 
here and there from the sun's " limb." Doubtless they 
rise also from other parts of the photosphere, though 
they are only visible to us when near enough to the 
edge to stand out beyond it. 

Seen during an eclipse, these prominences have 
clear, sharp outlines, and are usually bright rose-red 
in color. They are described as sometimes wide and 
low, sometimes tall and slender; sometimes jagged, 
sometimes regular; sometimes keeping long the same 
shape, sometimes changing quickly in a few minutes. 
They are said to be like flames, like mountains, like 
the teeth of a saw, like icebergs, like floating cloud- 
lets. 

As to their height, from fifty to eighty thousand 
miles is nothing unusual. We must not speak of 
Mont Blanc or Mount Everest here. Jupiter placed 
bodily on the surface of the sun, beside such a fire- 
mountain, would not far overtop it. The earth, Venus, 
Mars, and Mercury, would lie like little toy-balls at its 
foot. And these are common-sized sun-flames. One 
was measured which reached to the enormous height 
of two hundred thousand miles. The spectroscope 
shows these solar prominences or jets to be made — at 
least in part — of burning hydrogen gas. 

Beyond the sierra or chromatosphere — that border 
of rippling, crimson flame-billows round the edge of 
the sun, with red flame-mountains rising out of it 
here and there — beyond these, stretches the corona. 
The corona, as seen from earth, is a bright, far-reach- 
ing glory of light, shining round the sun in a total 
eclipse. The moon then comes between he sun and 



152 STORY OK THE) SUN, MOON, AND STARS. 

the earth, her dark, round body creeping over the face 
of the sun till the bright photosphere is completely 
covered. But the sierra and the tall, red flames stand 
out from behind the black moon, and the beautiful, 
soft corona-light stretches far beyond. 



SOLAR CORONA AND PROMINENCE. 

It was long doubted whether the corona really be- 
longed to the sun or to the moon. There seems now 
no doubt that it is a part of the sun. 

Various descriptions of the corona have been 
given at different times, as observed during different 



YET MORE ABOUT THE SUN. 1 53 

eclipses. It has been seen as a steady, beamy, white 
cloud behind the moon, showing no flickering. It has 
been seen marked with bright lines of light, and seem- 
ing to move rapidly round and round. It has been 
seen silvery white, sending off long streams of bright- 
ness. It has been seen in the form of white light, 
with bluish rays running over it. It has been seen 
with entangled jets of light, like "a hank of thread in 
disorder." It has been seen silvery- white again, with 
a faint tinge of greenish-violet about the outer edge. 
It has been seen from a high mountain-top as a mass 
of soft, bright light, "through which shot out, as if 
from the circumference of the moon, straight, massive, 
silvery rays, seeming distinct and separate from each 
other, to a distance of two or three diameters of the 
lunar disk, the whole spectacle showing as upon a 
background of diffused, rose-colored light." 

Majestic, indeed, are the proportions of some of 
those mighty flames which leap from the surface of 
the sun, yet these flames nicker, as do our terrestrial 
flames, when we allow them time comparable to their 
gigantic dimensions. Drawings of the same promi- 
nence often show great changes in a few hours, or even 
less. The magnitude of the changes could not be less 
than many thousands of miles, and the actual velocity 
with which such masses move is often not less than 
one hundred miles a second. Still more violent are 
the solar convulsions, which some observers have been 
so fortunate as to behold, when from the sun's surface, 
as from a mighty furnace, vast incandescent masses 
are projected upwards. All indications point to the 
surface of the sun as the seat of the most frightful 



154 STORY OF THE SUN, MOON, AND STARS. 

storms and tempests, in which the winds sweep along 
incandescent vapors. 

The corona consists of two parts — the inner and 
brighter corona, the onter and fainter corona. The 
shape of the whole seems to change much at different 
times. The outer edge is usually blurred and indis- 
tinct, fading gently away. 

Many explanations have been suggested. At one 
time the corona was supposed to be a solar atmos- 
phere, reflecting light like our own atmosphere. Some 
have thought the light might be caused by countless 
myriads of meteorite systems, revolving in the close 
neighborhood of the sun. Some suppose it may be 
owing, in part at least, to solar eruptions, and the 
pouring outward of burning gas and matter. But our 
knowledge of the true nature of the corona is yet in 
its infancy. 

A few closing words as to the size and weight of 
the sun. In diameter, eight hundred and fifty-eight 
thousand miles, and in bulk equal to one million two 
hundred and eighty thousand earths, his weight is in 
proportion less. Our earth is about four times as 
dense as the sun. If her size were increased to the 
sun's size, her density being the same as now, she 
would be very much heavier than the sun, and would 
attract much more strongly. Still, though the sun is 
of lighter materials than the earth, his immense size 
gives him weight equal to seven hundred and fifty 
times as much as all the planets put together. 

The attraction on the surface of the sun is also 
very great — so great that we can hardly picture it to 
ourselves. If life exists there at all — supposing it 



YET MORE ABOUT THE SUN. 1 55 

possible that any kind of life can be in such a fiery 
atmosphere — it must be life very different from any 
known in this world. A man who on earth weighs 
one hundred and sixty pounds, and walks lightly erect, 
would, on the sun, lie helplessly bound to the ground, 
crushed by his own overpowering weight. It is said 
that a cannon-ball, reposing on the sun, if lifted one 




COMPARATIVE SIZE OF THE EARTH AND SUN. 

inch and allowed to fall, would dash against the 
ground with a speed three times greater than that of 
our fastest express-trains. For weight on earth is 
merely caused by the amount of force with which the 
earth draws downward a body towards herself — a 
force greater or less according to the density of that 
body. So weight on the sun would be immensely 
increased by his immensely greater power of at- 
traction. 



I56 STORY OF THE SUN, MOON, AND STARS. 

It is an interesting question how far the sun's at- 
tractive influence reaches effectually through space. 
The nearer a body is to the sun, the greater the at- 
traction which he exercises over it. At the distance 
of the planet Mercury, a speed of twenty-nine miles 
each second is needful to overcome or balance it suffi- 
ciently for the planet to remain in his orbit. At the 
distance of the planet Neptune, about three miles 
each second is enough. If a planet were journeying 
at four times the distance of Neptune, the speed would 
need to be not over two miles each second, lest the 
planet should break loose and wander away. But 
even two miles a second is no mean speed — more 
than seven thousand miles an hour. If we come to 
speak of that which we on earth call rapid motion, 
we shall gain a clearer idea as to the extent of the 
sun's power. 

Suppose a planet were traveling through space at 
the rate of one of our fastest express-trains — sixty 
miles an hour. It has been calculated that, unless 
the sun's attraction were interfered with and over- 
powered by some nearer sun, the said planet, though 
placed at a distance ten or twelve times as great as 
that of the far-off star Alpha Centauri, would still be 
forced by the sun's attraction to journey round him in 
a closed orbit. At such a speed it would not be free 
to wander off into the depths of space. 



CHAPTER XIV. 

MORE ABOUT THE MOON. 

From a globe all fire, all energy, all action, we 
come to a globe silent, voiceless, changeless, lifeless. 
So, at least, the moon seems to us. But it will not do 
to speak too confidently. 

True, we can find no trace of an atmosphere in the 
moon. If there is any atmosphere at all, it must be 
so thin as to be less than that which we on earth 
count as actually none. We pump away the air from 
a glass inclosure in an air-pump, and say the glass 
is empty. Only it is not quite empty. There is al- 
ways just a very little air remaining, though so little 
that fire would not burn and animals could not live in 
it. Some believe that air, up to that amount, may be 
found in the moon. But this is much the same as to 
.say there is none at all. For, of course, with either 
no air or so very little air, life can not possibly exist 
on the moon. We can not imagine such a thing for a 
moment. That is just how the matter stands. We 
" can not imagine," and therefore we conclude it to be 
an impossibility. As if we knew a hundredth part of 
the possibilities in any one corner of God's great uni- 
verse! As if our being unable to picture a thing 
proves that thing not to exist ! 

Suppose we had always lived in tropical heat, and 
had never seen, known, or heard of such a fact as life 
in Arctic snows. Should we consider it a thing pos- 
• 157 



I58 STORY OF THE SUN, MOON, AND STARS. 

sible ? Suppose we had always lived on dry land, with 
never a sight of sea or river or pond, and never a 
proof that animal life could exist under water — aye, 
and that some living animals may be suffocated by 
air, just as other living animals are suffocated by 
water. Should we not, in our wisdom, reason out 
such a state of affairs to be utterly impossible? 

There may be no life on the moon. Jt may be that 
she is now passing through a dead, cold, blasted stage, 
either at the close of some past history, or in prepara- 
tion for some future history — or both. But, on the 
other hand, it may be that the moon is no less full of 
life than the earth; only the life must be different in 
kind, must be something which we do not know any 
thing at all about. 

The moon is very much smaller than the earth. 
Her diameter is about two-sevenths of the earth's di- 
ameter; her entire surface is about two twenty-sev- 
enths of the earth's surface ; her size is about two 
ninety-ninths of the earth's size ; and her whole weight 
is about one-eightieth of the earth's weight. Attrac- 
tion or gravitation on the surface of the moon is very 
different from what it is on the earth. Her much 
smaller bulk greatly lessens her power of attraction. 
While a man from earth would, on the surface of 
the sun — supposing he could exist there at all— lie 
helpless, motionless, and crushed by his own weight, 
he would on the moon find himself astonishingly light 
and active. A leap over a tall house would be noth- 
ing to him. 

The moon, unlike the sun, has no light or heat of 
her own to give out. She shines merely by reflected 



MORE ABOUT THE MOON. 



159 



light. Rays of sunlight falling upon her, rebound 
thence, and find their way earthward. This giving of 




THE MOON — AN EXPIRED PLANET. 



reflected light is not a matter all on one side. We 
yield to the moon a great deal more than she yields 
to us. Full earth, seen from the moon, covers a 



l6o STORY OF THE SUN, MOON, AND STARS. 

space thirteen times as large as full moon seen from 
earth. 

Perhaps you may have noticed, soon after new 
moon, when a delicate crescent of silver light shows 
in the sky, that within the said crescent seems to lie 
the body of a round, dark moon, only not perfectly 
dark. It shows a faint glimmer. That glimmer is 
called earth-shine. The bright crescent shines with 
reflected sunlight. The dim portion shines with re- 
flected earth-light. What a journey those rays have 
had! First, leaving the sun, flashing through ninety- 
three millions of miles to earth, rebounding from earth 
and flashing over two hundred and forty thousand 
miles to the dark shaded part of the moon, then 
once more rebounding and coming back, much wasted 
and enfeebled, across the same two hundred and forty 
thousand miles, to shine dimly in your eyes and mine. 
The popular description of this particular view of the 
moon is " the old moon in the arms of the new." 

Now about the phases of the moon ; that is, her 
changes from "new" to "full," and back again to 
"new." If the moon were a starlike body, shining 
by her own light, she would always appear to be 
round. But as she shines by reflected sunlight, and 
as part of her bright side is often turned away from 
us, the size and shape of the bright part seem to vary. 
For, of, course, only that half of the moon which is 
turned directly towards the sun is bright. The other 
half turned away is dark, and can give out no light at 
all, unless it has a little earth-shine to reflect. 

As the moon travels round the earth, she changes 
gradually from new to full moon, and then back to 



MORE ABOUT THE MOON. l6l 

new again. "New moon" is when the moon, in her 
orbit, comes between the sun and the earth. The 
half of her upon which the sun shines is turned away 
from us, and only her dark side is towards us. So at 
new moon she is quite invisible. It is at new moon 
that an eclipse of the sun takes place, when the 
moon's orbit carries her in a line precisely between 
sun and earth. 

Passing onwards round the earth, the moon, as we 
get a little glimpse of her shining side, first shows a 
slender sickle of light, which widens more and more 
till she reaches her first quarter. She is then neither 
between earth and sun, nor outside the earth away 
from the sun, but just at one side of us, passing over 
the earth's own orbit. Still, as before, half her body 
is lighted up by the sun. By this time half the bright 
part and half the dark part are turned towards us; so 
that, seeing the bright quarter, we name it the ' ' first 
quarter." 

On and on round us moves the moon, showing 
more light at every step. Now she passes quite out- 
side the earth's orbit, away from the sun. Not the 
slightest chance here of an eclipse of the sun, though 
an eclipse of the moon herself is quite possible. But 
more of that presently. As she reaches a point in a 
line with earth and sun — only generally a little higher 
or lower than the plane of the earth's orbit — her 
round, bright face, shining in the sun's rays, is turned 
exactly towards us. Then we have "full moon." 

Still she goes on. Once more her light narrows 
and wanes, as part of her bright half turns away. 
Again at the "last quarter," as at the first, she occu- 



1 62 STORY OF THE SUN, MOON, AND STARS. 

pies a "sideways" position, turning towards us half 
her bright side and half her dark side. Then she 
journeys on, with lessening rim of light, till it van- 
ishes, and once more we have the dark, invisible 
"new moon." 

It was these phases and aspects of the moon which 
formerly gave birth to the custom of measuring time 
by months, and by weeks of seven days, on account of 
the return of the moon's phases in a month, and be- 
cause the moon appears about every seven days, so to 
say, under a new form. Such was the first measure of 
time ; there was not in the sky any signal of which 
the differences, the alternations, and the epochs were 
more remarkable. Families met together at a time 
fixed by some lunar phase. 

The new moons served to regulate assemblies, sac- 
rifices, and public functions. The ancients counted 
the moon from the day they first perceived it. In or- 
der to discover it easily, they assembled at evening 
upon the heights. The first appearance of the lunar 
crescent was watched with care, reported by the high 
priest, and announced to the people by the sound of 
trumpets. The new moons which correspond with the 
renewal of the four seasons were the most solemn ; we 
find here the origin of the "ember weeks" of the 
Church, as we find that of most of our festivals in the 
ceremonies of the ancients. The Orientals, the Chal- 
deans, Egyptians, and Jews religiously observed this 
custom. 

An eclipse of the sun has already been described. 
An eclipse of the moon is an equally simple matter. 
An eclipse of the sun is caused by the dark, solid 



MORE ABOUT THE MOON. 163 

body of the moon passing just between earth and sun, 
hiding the sun from us, and casting its shadow upon 
the earth. An eclipse of the moon is also caused by 
a shadow — the shadow of our own earth — falling upon 
the moon. 

Here again, if the plane of the moon's orbit were 
the same as ours, eclipses of the moon would be very 
common. As it is, her orbit carries her often just a 
little too high or too low to be eclipsed, and it is only 
now and then, at regular intervals, that she passes 
through the shadow of the earth. 

If a large, solid ball is hung up in the air, with 
bright sunlight shining on it, the sunlight will cast a 
cone of shadow behind the ball. It will throw, in a 
direction just away from the sun, a long, round shadow, 
the same as the ball at first, but tapering gradually off 
to a point. If the ball is near the ground, a round 
shadow will rest there, almost as large as the ball. 
The higher the ball is placed, the smaller will be the 
round shadow, till at length, if the ball be taken far 
enough upwards, the shadow will not reach the ground 
at all. Our earth and all the planets cast just such 
tapering cones of dark shadow behind them into space. 
The cone always lies in a direction away from the sun. 

It is when the moon comes into this shadow that 
an "eclipse of the moon" takes place. Sometimes 
she only dips half-way into it, or just grazes along 
the edge of it, and that is called a "partial eclipse." 
Sometimes she goes in altogether, straight through 
the midst of the shadow, so that the whole of her 
bright face for a short time grows quite dark. Then 
we have a "total lunar eclipse." 



CHAPTER XV. 

YET MORE ABOUT THE MOON. 

There are two ways of thinking abont the moon. 
One way is to consider her as merely the earth's 
attendant satellite. The other w T ay is to consider 
her as our sister-planet, traveling with us round the 
central sun. 

The first is the more common view ; but the second 
is just as true as the first. 

For the sun does actually pull the moon towards 
himself, with a very much stronger pulling than that 
of the earth. The attraction of the sun for the moon 
is more than double the attraction of the earth for the 
moon. If it were not that he pulls the earth quite as 
hard as he pulls the moon, he would soon overpower 
the earth's attraction, and drag the moon away from 
us altogether. 

People are often puzzled about the orbit or path- 
way of the moon through the heavens. For in one 
sense they have to think of her as traveling round 
and round in a fixed orbit, with the earth in the 
center. In another sense they have to think of her 
as always journeying onwards with the earth in her 
journey round the sun, and thus never returning to 
the same point. 

There are two ways of meeting this difficulty. 
First of all, remember that the one movement does 
not interfere with the other. Just as in the case of 

164 



YET MORE ABOUT THE MOON. 165 

the earth traveling round the sun, and also traveling 
onward with him through space ; just as in the case 
of a boy walking round and round a mast, and also 
being borne onwards by the moving vessel, — so it is 
here. The two movements are quite separate and 
independent of each other. As regards the earth 
alone, the moon journeys round and round perpet- 
ually, not in a circle, but in a pathway which comes 
near being an ellipse. As regards the actual line 
which the moon's movements may be supposed to 
draw in space, it has nothing elliptical about it, since 
no one point of it is ever reached a second time by 
the moon. 

But according to this last view of the question, no- 
body ever can or will walk in a circle or an oval. 
Take a walk round your grass-plot, measuring your 
distance carefully at all points from the center. Is 
that a circle ? All the while you moved, the surface 
of the earth was rushing along and bearing you with 
it, and the whole earth was hurrying round the sun, 
and was being also carried by him in a third direc- 
tion. Whatever point in space you occupied when 
you started, you can never fill that particular part of 
space again. The two ends of your so-called circle 
can never be joined. 

But then you may come back to the same point on 
the grass, as that from which you started. And this 
is all that really signifies. Practically you have 
walked in a circle. Though not a circle as regards 
space generally, it is a circle as regards the earth. 
So also the moon comes back to the same point in 
her orbit round the earth. Letting alone the question 



1 66 STORY OF the: sun, moon, and stars. 

of space, and considering only the earth, the moon 
has — roughly speaking — journeyed in an ellipse. 
You may, however, look at this matter in quite an- 
other light. Forget about the moon being the earth's 
satellite, and think of earth and moon as two sister- 
planets going round the sun in company. 

The earth, it is true, attracts the moon. So, also, 
the moon attracts the earth ; though the far greater 
weight of the earth makes her attraction to be far 
greater. If earth and moon were of the same size, 
they would puil each other with equal force. 

But though the pull of the earth upon the moon is 
strong, the pull of the sun upon the moon is more 
than twice as strong. And greatly as the earth influ- 
ences the moon, yet the actual center of the moon's 
orbit is the sun, and not the earth. Just as the earth 
travels round the sun, so also the moon travels round 
the sun. 

The earth travels steadily in her path, being only 
a little swayed and disturbed by the attraction of the 
moon. The moon on the contrary, while traveling 
in her orbit, is very much swayed and disturbed in- 
deed by the earth's attraction. In fact, instead of 
being able to journey straight onwards like the earth, 
her orbit is made up of a succession of delicate curves 
or scallops, passing alternately backwards and forwards 
over the orbit of the earth. Now she is behind the 
earth ; now in front of the earth ; now between earth 
and sun; now outside the earth away from the sun. 
The order of positions is not as here given, but each 
is occupied by her in turn. Sometimes she moves 
quickly, sometimes she moves slowly, just according 



YET MORE ABOUT THE MOON. 167 

to whether the earth is pulling her on or holding her 
back. Two hundred and forty thousand miles sounds a 
good deal. That is the distance between earth and 
moon. But it is, after all, a mere nothing, compared 
with the ninety-three millions of miles which separate 
the sun from the earth and moon. 

If we made a small model, with the sun in the 
center, and the earth and moon traveling a few inches 
off, only one slender piece of wire would be needed 
to represent the path of earth and moon together. 
For not only would the earth and the moon be so 
small as to be quite invisible, but the whole of the 
moon's orbit would have disappeared into the thick- 
ness of the single wire. This question of the moon's 
motions is in its nature intricate, and in its details 
quite beyond the grasp of any beginner in astronomy. 
But so much at least may be understood, that 
though the earth's attraction powerfully affects the 
moon, and causes in her motions pertnrbatio7is, such as 
have been already spoken about as taking place among 
the planets, yet that in reality the great controlling 
power over the moon is the attraction of the sun. 

The tides of the ocean are chiefly brought about 
by the moon's attraction. The sun has something to 
do with the matter, but the moon is the chief agent. 
This action of the moon can best be seen in the south- 
ern hemisphere, where there is less land. As the 
moon travels slowly round the earth, her attraction 
draws up the yielding waters of the ocean in a vast 
wave which travels slowly along with her. The same 
pulling which thus lifts a wave on the side of the 
earth towards the moon, also pulls the earth gently 



l68 STORY OF THE SUN, MOON, AND STARS. 

away from the water on the opposite side, and causes 
a second wave there. The parts of the ocean between 
these two huge waves are depressed, or lower in level. 
These two waves on the opposite sides of the earth 
sweep steadily onwards, following the moon's move- 
ments, — not real, but seeming movements, caused by 
the turning of the earth upon her axis. 

Once in every twenty-four hours these wide waves 
sweep round the whole earth in the southern ocean. 
They can not do the same in the north, on account of 
the large continents, but offshoots from the south 
waves travel northwards, bringing high-tide into every 
sea and ocean inlet. If there were only one wave, 
there would be only one tide in each twenty-four 
hours. As there are two waves, there are two tides, 
one twelve hours after the other. In the space be- 
tween these two high-tides we have low-tide. 

Twice every month we have very high and very low 
tides. Twice every month we have tides not so high 
or so low. The highest are called " spring- tides," and 
the lowest "neap-tides." When the moon is between 
us and the sun, or when she is "new moon," there are 
spring-tides; for the pull or attraction of sun and 
moon upon the ocean act exactly together. It is the 
same at full moon, when once more the moon is in a 
straight line with earth and sun. But at the first and 
last quarters, when the moon has her sideways posi- 
tion, and when the sun pulls in one direction and the 
moon pulls in another, each undoes a little of the 
other's work. Then we only have neap-tides ; for the 
wave raised is smaller, and the water does not flow so 
high upon our shores. 



YET MORE ABOUT THE MOON. 169 

In speaking of the surface of the moon, we are 
able only to speak about one side. The other is 
entirely hidden from us. This is caused by the 
curious fact that the moon turns on her axis and 
travels round the earth in exactly the same length of 
time. One-half of the moon is thus always turned to- 
wards us, though of that half we can only see so much 
as is receiving the light of the *sun. But the half 
turned in our direction is always the same half. 
One part of the moon — not quite so much as half, 
though always the same portion — is turned away from 
us. A small border on each side of that part becomes 
now and then visible to us, owing to certain move- 
ments of the earth and the moon. 

What sort of a landscape may lie in the unknown 
district, it is idle to imagine. Many guesses have 
been made. Some have supposed it possible that air 
might be found there ; that water might exist there ; 
that something like earthly animals might live there. 
It is difficult to say what may not be, in a place about 
which we know nothing whatever. But judging from 
our earthly experience, nothing seems more unlikely 
than that air, water, clouds, should be entirely ban- 
ished from over one-half of a globe, and collected to- 
gether in the space remaining. 

We are on safer ground when we speak about that 
part of the moon which is turned towards us. For we 
can say with confidence that if any atmosphere exist 
there, it must be in thickness less than the two-thou- 
sandth part of our earthly atmosphere. It seems 
equally clear that water also must be entirely wanting. 
The tremendous heat of the long lunar day would 



170 STORY OF THE SUN, MOON, AND STARS. 

raise clouds of vapor, which could not fail to be visible. 
But no such mistiness ever disturbs the sharply-defined 
outline of the moon, and no signs of water action are 
seen in the craggy mountains and deep craters. 

The craters which honeycomb the surface of the 




THE EUNAR CRATER COPERNICUS. 



moon are various in size. Many of the larger ones 
are from fifty to a hundred miles in diameter. These 
huge craters — or, as we may call them, deep circular 
plains — are surrounded by mighty mountain ram- 
parts, rising to the height of thousands of feet. 
Usually they have in their center a sugar-loaf or 



YET MORE ABOUT THE MOON. 171 

cone-shape mountain, or even two or more such 
mountains, somewhat lower in height than the sur- 
rounding range. The sunset-lights upon certain of 
these distant mountain-peaks were first watched by 
Galileo through his telescope, and have since been 
seen by many an observer — intense brightness con- 
trasting with intense blackness of shadow. 

In addition to her great craters, the moon seems 
to be thickly covered with little ones, many of them 
being as small as can be seen at all through a telescope. 
Whether these are all volcano-craters remains to be 
discovered. It is not supposed that any of them are 
now active. From time to time, signs of faint changes 
on the moon's surface have been noticed, which it 
was thought might be owing to volcanic outbursts. 
Such an outburst as the worst eruptions of Mount 
Vesuvius would be invisible at this distance. But the 
said changes may be quite as well accounted for by 
the startling fortnightly variations of climate which 
the moon has to endure. The general belief now in- 
clines to the idea that the moon-volcanoes are extinct, 
though no doubt there was in the past great volcanic 
activity there. 

A description has been given earlier of the rain of 
meteorites constantly falling to our earth, and only 
prevented by the atmosphere from becoming serious. 
But the moon has no such protecting atmosphere, and 
the amount of cannonading which she has to endure 
must be by no means small. Perhaps in past times, 
when her slowly-cooling crust was yet soft, these ce- 
lestial missiles showering upon her may have occa- 
sionally made deep round holes in her surface. 



172 STORY OF THE SUN, MOON, AND STARS. 

This is another guess, which time may prove to be 
true. Guesses at possible explanations of mysteries 
do no harm, so long as we do not accept them for 
truth without ample reason. 

The origin of the lunar craters must be referred 
to some ancient epoch in the moon's history. How 
ancient that epoch is we have no means of knowing; 




I,UNAR ERUPTION — BRISK ACTION. 

but in all probability the antiquity of the lunar craters 
is enormously great. At the time when the moon 
was sufficiently heated to have these vast volcanic 
eruptions, of which the mighty craters are the sur- 
vivals, the earth must have been ver}' much hotter 
than it is at present. It is not, indeed, at all unrea- 
sonable to believe that when the moon was hot enough 
for its volcanoes to be active, the earth was so hot that 
life was impossible on its surface. This supposition 



YET MORE ABOUT THE MOON. 



173 



would point to an antiquity for the moon's craters far 
too great to be estimated by the centuries and the 
thousands of years which are adequate for the lapse 
of time as recognized by the history of human events. 
It seems not unlikely that millions of years may have 
elapsed since the mighty craters of Plato or of Coper- 
nicus consolidated into their present form. 




LUNAR ERUPTION— FEEBLE ACTION. 



It will now be possible for us to attempt to ac- 
count for the formation of the lunar craters. The 
most probable views on the subject are certainly those 
adopted by Mr. Nasmyth, as represented in the cuts, 
though it must be admitted that they are by no means 
free from difficulty. We can explain the way in which 
the rampart around the lunar crater is formed, and 
the great mountain which so often adorns the center 
of the plain. The first of these cuts contains an im- 



174 STORY OF THE SUN, MOON, AND STARS. 

aginary sketch of a volcanic vent on the moon in the 
days when the craters were active. The eruption is 
here in the full flush of its energy, when the internal 
forces are hurling forth a fountain of ashes or stones, 
which fall at a considerable distance from the vent ; and 
these accumulations constitute the rampart surround- 
ing the crater. The second cut depicts the crater in 
a later stage of its history. The prodigious explosive 
power has now been exhausted, and perhaps has been 
intermitted for some time. A feeble jet issues from 
the vent, and deposits the materials close around the 
orifice, and thus gradually raises a mountain in the 
center. 

Besides the craters and their surrounding barriers, 
there are ranges of mountains on the moon, and flat 
plains which were once named "seas," before it was 
found that water did not exist there. Astronomers 
also see bright ridges, or lines, or cracks of light, hard 
to explain. 

One of the chief craters is called " Ptolemy," and 
in size it is roughly calculated to be no less than one 
hundred and fourteen miles across. Another, "Co- 
pernicus," is about fifty-six miles; and another, 
"Tycho," about fifty-four miles. The central cone- 
mountain of Tycho is five thousand feet high. The 
crater of "Schickard" is supposed to be as much as 
one hundred and thirty-three miles in diameter. 

Astronomers have agreed to name these craters 
after the great discoverers who enlarged our knowl^ 
edge of the solar and sidereal systems. It is fitting 
that these great names are suggested every time the 
moon is seen through a telescope. To Ptolemy we 



YET MORE ABOUT THE MOON. 1 75 

are indebted for what is known as "The Ptolemaic 
System of the Universe," which makes the earth the 
center aronnd which the snn, moon, planets, and stars 
all revolve, and explains the apparently erratic move- 
ments of the planets by supposing their orbits to be 
epicycles; that is, curves returning upon themselves 
and forming loops. Tycho Brahe was willing to allow, 
with Copernicus, that the planets all revolved around 
the sun; but he taught that both sun and planets 
turned around the earth. 

The system known as "The Copernican ,, is now 
known to be the only true one, and it is universally 
accepted. It is so called after Nicolaus Copernicus, 
who was born in Thorn, Prussia, February 19, 1473. 
He was educated for the Church, and studied medi- 
cine, but devoted himself especially to astronomy. 

Without being precisely a great genius, this quiet 
and thoughtful monk seems to have been wise far 
beyond the age in which he lived, and remarkable 
for his independence of mind. He had a "profound 
sagacity," and a wide general grasp of scientific 
subjects. 

The extremely complicated and cumbrous nature 
of the Ptolemaic system appeared to his judgment 
hardly compatible with the harmony and simplicity 
elsewhere characteristic of nature. Moreover, he was 
impressed and perplexed by the very marked changes 
in the brilliancy of the planets at different seasons. 
These changes now are no difficulty at all. Venus, 
Mars, Jupiter, when on the same side of the sun as 
ourselves, are comparatively near to us, and naturally 
look much more bright in consequence of that near- 



176 STORY OF THE SUN, MOON, AND STARS. 

ness than when they are on the opposite side of the 
sun from ourselves. But under the Ptolemaic system, 
each planet was supposed to revolve round our earth, 
and to be always at about the same distance from us; 
therefore, why such variations in their brilliancy? 




NICOI^AUS COPERNICUS. 



During thirty-six long years he patiently worked 
out this theory, and during part of those thirty-six 
years he wrote the one great book of his lifetime, ex- 
plaining the newer view of the Solar System which 



YET MORE ABOUT THE MOON. 1 77 

had taken hold of his reason and imagination. This 
book, named De Revolutionibus Orbium Ccelestium, 
or, " Concerning the Revolutions of the Celestial 
Spheres," which came out only a few hours before his 
death, was dedicated to the Bishop of Rome — a little 
touch of worldly wisdom which doubtless staved off 
for a while the opposition of the Vatican. 

Copernicus was not the first who thought of in- 
terpreting the celestial motions by the theory of the 
earth's motion. That immortal astronomer has taken 
care to give, with rare sincerity, the passages in the 
ancient writers from which he derived the first idea of 
the probability of this motion — especially Cicero, who 
attributed this opinion to Nicetas of Syracuse; Plu- 
tarch, who puts forward the names of Philolaus, He- 
raclides of Pontus, and Ecphantus the Pythagorean; 
Martianus Capella, who adopted, with the Egyptians, 
the motion of Mercury and Venus around the sun, etc. 
Even a hundred years before the publication of the 
work of Copernicus, Cardinal Nicolas of Cusa, in 1444, 
in his great theological and scientific encyclopedia, 
had also spoken in favor of the idea of the earth's 
motion and the plurality of worlds. From ancient 
times to the age of Copernicus, the system of the 
earth's immobility had been doubted by clear-sighted 
minds, and that of the earth's motion was proposed 
under different forms. But all these attempts still 
leave to Copernicus the glory of establishing it defi- 
nitely. 

Not content with merely admitting the idea of the 
earth's motion as a simple arbitrary hypothesis, which 
Several astronomers had done before him, he wished — 



178 story o^ The: Sun, moon, and stars. 

and this is his glory — to demonstrate it to himself by- 
acquiring the conviction by study, and wrote his book 
to prove it. The true prophet of a creed, the apostle 
of a doctrine, the author of a theory, is the man who, 
by his works, demonstrates the theory, makes the 
creed believed in, and spreads the doctrine. He is 
not the creator. "There is nothing new under the 
sun," says an ancient proverb. We may rather say, 
Nothing which succeeds is entirely new. The new- 
born is unformed and incapable. The greatest things 
are born from a state of germ, so to say, and increase 
unperceived. Ideas fertilize each other. The sciences 
help each other; progress marches. Men often feel a 
truth, sympathize with an opinion, touch a discovery, 
without knowing it. The day arrives when a syn- 
thetical mind feels in some way an idea, almost ripe, 
becoming incarnate in his brain. He becomes enam- 
ored of it, he fondles it, he contemplates it. It grows 
as he regards it. He sees, grouping round it, a mul- 
titude of elements which help to support it. To him 
the idea becomes a doctrine. Then, like the apostles 
of good tidings, he becomes an evangelist, announces 
the truth, proves it by his works, and all recognize in 
him the author of the new contemplation of nature, 
although all know perfectly well that he has not in- 
vented the idea, and that many others before him have 
foreseen its grandeur. 

Such is the position of Copernicus in the history of 
astronomy. The hypothesis of the earth's motion had 
been suggested long before his birth on this planet. 
This theory counted partisans in his time But he — 
he did his work. He examined it with the patience 



YET MORE ABOUT THE MOON. 179 

of an astronomer, the rigor of a mathematician, the 
sincerity of a sage, and the mind of a philosopher. 
He demonstrated it in his works. Then he died with- 
out seeing it understood, and it was not till a century 
after his death that astronomy adopted it, and popular- 
ized it by teaching it. However, Copernicus is really 
the author of the true system of the world, and his 
name will remain respected to the end of time. 

The so-called " seas' ' on the moon are those large 
dark spots to be seen on its surface, in the shape of 
"eyes, nose, and mouth," or of the famous old man 
with his bundle of sticks. The brighter parts are the 
more mountainous parts. 

The chief ranges of lunar mountains have been 
named by astronomers after mountains on earth, such 
as the Apennines, the Alps, the Caucasian range, the 
Carpathian and the Altai Mountains. 



CHAPTER XVI. 

MERCURY, VENUS, AND MARS. 

Once again we have to journey through the high- 
roads of the Solar System, paying a brief visit to each 
in turn of our seven chief brother-and-sister planets, 
and learning a few more leading facts about them. 
Having gone the same way before, it will not now seem 
quite so far. 

Busy, hurrying Mercury! we must meet him first 
in his wild rush through space. If he were to slacken 
speed for a single instant, he would begin to fall with 
fearful rapidity towards the sun. And if Mercury 
were to drop into one of those huge black chasms of 
rent furnace-flame on the sun's surface, there would be 
a speedy end to his life as a planet. 

Mercury's day is about the same length as our day, 
and his year is about one quarter the length of our 
year. If Mercury has spring, summer, autumn, and 
winter, each season must be extremely short; but this 
depends upon whether Mercury's axis slopes like the 
earth's axis — a matter difficult to find out. Mercury 
is always so near to the sun, that it is by no means 
easy to observe him well. 

We know more about his orbit than his axis. The 
earth's orbit, as before explained, is not a circle, but 
an ellipse or oval. Mercury's orbit is an ellipse also, 
and a much longer — or, as it is called, a more eccen- 
tric — ellipse. The earth is three millions of miles 

t8o 



MERCURY, VENUS, AND MARS. l8l 

nearer to the sun at one time of the year, than six 
months before or after. Mercury is no less than fif- 
teen millons of miles nearer at one time than another, 
which must make a marked difference in the amount 
of heat received. 

Even when the distance is greatest, the sun as seen 
from Mercury looks four and a half times as large as 
the sun we see. What a blazing splendor of light! 
It is not easy to imagine human beings living there, 
in such heat and glare, and with either no changes of 
season at all, or such very short seasons rapidly fol- 
lowing one another. Mercury may, and very likely 
does, abound with living creatures, as much as the 
earth abounds with them ; only one fancies they must 
be altogether a different kind of living creatures from 
any ever seen on earth. And yet we do not know. Man 
can so wonderfully adapt himself or be adapted to dif- 
ferent climates on earth, from extreme heat to extreme 
cold, that we can not tell how far this adapting power 
may reach. 

Both Mercury and Venus seem to be enfolded in 
dense, cloud-laden atmospheres, rarely parting so as 
to allow us to get even a glimpse of the real planets 
within the thick, light-reflecting covering. Some 
have thought that a heavy, moist, protecting atmos- 
phere may help to ward off the intense heat, and to 
make Mercury a more habitable place. Our earthly 
atmosphere is rather of a kind to store up heat, and 
to make us warmer than we should be without it; but 
there might be vapors differently constituted which 
might act in some other way. At all events, we know 
how easily God can have adapted either the planet 



l82 STORY OF THE SUN, MOON, AND STARS. 

to the creatures he meant to place there, or the crea- 
tures to the climate. "All things are possible" to 
him. The how and the what are interesting questions 
for us, but we must often be content to wait for an 
answer. 

A thick, gray ring or belt has been noticed round 
the small, black disk of Mercury, while it has passed 
between us and the sun. The edge of Mercury, seen 
against the bright photosphere beyond, would, if there 
were no atmosphere, be sharp and clear as the edge of 
the airless moon. This surrounding haze seems to 
show that Mercury has an atmosphere. The sunlight 
reflected from Mercury's envelope of clouds shines at 
least as brightly as if it were reflected from his solid 
body. 

The small size of Mercury makes attraction on his 
surface much less than on earth. A lump of iron 
weighing on earth one pound, would weigh on Mer- 
cury only about seven ounces, or less than half as 
much. So a man would be a very light leaper indeed 
there, and an elephant might be quite a frolicsome 
animal. If there are star-gazers in Mercury, and if 
the cloud-laden atmosphere allows many clear views 
of the sky, the earth and Venus must both be beau- 
tiful to look upon. Each of the two would shine far 
more brightly than Jupiter, as seen at his best from 
earth. 

Like Mercury, Venus, the next planet, has an orbit 
lying inside our orbit. Mercury and Venus are al- 
ways nearer to the sun than we are ; and if Mercury 
and Venus traveled round the sun in orbits, the planes 
of which were exactly the same as the plane of the 



MERCURY, VENUS, AND MARS. 183 

earth's orbit, we should very often see them creeping 
over the surface of the sun. Not that they really 
" creep over " it ; only, as they journey between the 
sun and us, we can see them pass like little black dots 
across the sun's disk. This is the same thing as when 
the moon passes across the sun's disk and eclipses it. 
But Mercury and Venus are too far away from us to 
cause any eclipse of the sun's light. 

Mercury has given more trouble to astronomers 
than any other member of the system; for, owing to 
his proximity to the sun, he is usually lost in the 
solar glory, and is never seen in a dark part of the 
heavens, even at the time of his greatest distance. 
This circumstance, together with a small mass and an 
immense velocity, renders it difficult to catch and watch 
him. In high latitudes, where the twilight is strong 
and lengthened, while mists often overhang the hori- 
zon, the planet can seldom be seen with the naked eye. 
Hence an old astro-meteorologist contemptuously de- 
scribes him as "a squirting lacquey of the sun, who 
seldom shows his head in these parts, as if he was in 
debt." Copernicus lamented that he had never been 
able to obtain a sight of Mercury ; and the French as- 
tronomer Delambre saw him not more than twice with 
the naked eye. 

The most favorable times for making observations 
are about an hour and three-quarters before sunrise in 
autumn, and after sunset in spring; but very clear 
weather and a good eye are required. At certain pe- 
riods, when between the earth and the sun, on a line 
joining the centers of the two bodies, Mercury ap- 
pears projected on the solar disk as a small, round, dark 



184 STORY OF THE SUN, MOON, AND STARS. 

spot. This is called a transit, and would occur during 
every revolution if the plane of his orbit coincided 
with that of the orbit of the earth. But as one-half 
of his orbit is a little above that of the earth, and the 
other half a little below it, he passes above or below 
the sun to the terrestial spectator, except at those in- 
tervals, when, being between us and the sun, he is 
also at one of the two opposite points where the planes 
of the respective orbits intersect each other. Then, 
stripped of all luster, the planet passes over the face 
of the great luminary as a black circular speck, af- 
fording evidence of his shining by reflected light, and 
of his spherical form. 

The first transit of Mercury recorded in history 
was predicted by Kepler, and witnessed by Gassendi, 
at Paris, on the morning of a cloudy day, the 7th of 
November, 1631. It was toward nine o'clock when he 
saw the planet; but owing to its extreme smallness, 
he was at first inclined to think it was a minute solar 
spot. It was then going off the sun; and made its 
final egress toward half-past ten. The observed time 
of the transit was nearly five hours in advance of the 
computed time. This was a very satisfactory accord- 
ance for that age between theory and observation ; but 
it was the effect of a fortuitous combination of circum- 
stances, rather than of computations founded upon 
well-established data. " The crafty god," wrote Gas- 
sendi, in the peculiar style of his day, "had sought to 
deceive astronomers by passing over the sun a little 
earlier than was expected, and had drawn a veil of 
dark clouds over the earth in order to make his escape 
more effectual. But Apollo, knowing his knavish 



i85 

tricks from his infancy, would not allow him to pass 
altogether unnoticed. To be brief, I have been more 
fortunate than those hunters after Mercury who have 
sought the cunning god in the sun. I found him out, 
and saw him where no one else had hitherto seen 
him." Since Gassendi's time a number of transits 
have been observed. 

These crossings of the sun's face, or " transits," as 
they are called, have been important matters. The 
transit of Venus especially was once eagerly looked 
for by astronomers, since, by close observations of Ve- 
nus's movements and positions, the distance of the 
sun could at that time be better calculated than in any 
other way. Other methods are now coming into vogue. 

The transits of Venus are rare. Two come near 
together, separated by only eight years, and then for 
more than one hundred years the little dark body of 
Venus is never seen from earth to glide over the sun's 
photosphere. There was a transit of Venus in the 
year 1761, and another in the year 1769. There was 
a transit of Venus in 1874, and another in 1882. At 
the last transits it was found that the sun, instead of 
being ninety-five millions of miles away, as astrono- 
mers thought, was only ninety- three millions of miles 
away. The reason why these transits happen so 
seldom, is that the orbits of Mercury and Venus lie in 
rather a different plane or level from the earth's orbit. 
So, like the moon, though often passing between us 
and the sun, they generally go just a little higher or 
just a little lower than his bright face. 

Mercury and Venus show phases like the moon, al- 
though they do not circle round the earth as the moon 



l86 STORY OF THK SUN, MOON, AND STARS. 

does. These " phases," or changes of shape, are prob- 
ably never visible except through a telescope. It will 
be easier to think about the phases of Venus alone, 
than to consider both together. Her orbit lies within 
the earth's orbit, and the earth and Venus travel round 
the sun — as do all the planets — in the same direction. 
But as Venus' s pathway is shorter than ours, and as 
her speed is greater, she is much the quickest about 
her yearly journey, and she overtakes us again and 
again at different points of our orbit in turn. 

At one time 
she comes be- 
tween us and 
the sun. That 
is her nearest 
position to us, 
and she is then 
only about 
twenty-five mill- 

PHASES OF VENVS. iotlS of DlileS dis- 

tant. A beautiful sight she would be, but unfortu- 
nately her bright side is entirely turned away, and 
only her dark side is turned towards us. So then she 
is "new Venus," and is invisible. 

At another time she is completely beyond the sun, 
and at her farthest position away from us. Her shin- 
ing is quite lost in the sun's rays coming between. 
And though we get a good view of her as " full Ve- 
nus," at a little to one side or the other, yet so great 
is her distance — as much as one hundred and fifty- 
seven millions of miles — that her size and brightness 
are very much lessened. 




MERCURY, VENUS, AND MARS. 1 87 

Between these two nearest and farthest points, she 
occupies two middle distances, one on each side of 
the sun. Then, like the moon at her " quarters," she 
turns to us only half of her bright side. But this is 
the best view of Venus that we have, as a brilliant, 
untwinkling, starlike form, — the Evening Star of an- 
cients and of poets. Between these four leading posi- 
tions Venus is always traveling gradually from one to 
another — always either waxing or waning in size and 
in brightness. Mercury passes through the same 
seeming changes. 

Inhabitants of Venus must have a glorious view of 
the earth, with her attendant moon. For just at the 
time when the two planets are nearest together, and 
when she is only "new Venus" to us, a dark and in- 
visible body, the earth is " full earth " to Venus. The 
very best sight we ever have of Venus can not come 
near that sight. But if Mercury and Venus really are 
so often covered with heavy clouds as astronomers be- 
lieve, this must greatly interfere with any habits of 
star-gazing. 

Venus and the earth have often been called twin- 
sister planets. There are many points of likeness be- 
tween them. In size they differ little, and in length 
of day they are within an hour of being the same. 
Earth certainly has a companion-moon, and Venus, it 
is believed, has not. At one time several astronomers 
were pretty certain that they had caught glimpses of a 
moon ; but the supposed moon has of late quite van- 
ished, and nobody can say whether it ever really ex- 
isted. Venus travels in an ellipse which comes nearer 
to being a circle than the orbit of any other planet. 



1 88 STORY OF THK SUN, MOON, AND STARS. 

Mountain-shadows have been watched through the 
telescope, in Venus, as in the moon. Some astrono- 
mers have believed that they saw signs of very lofty 
mountains — as much as twenty-eight miles, or four 
times the height of our highest earthly mountains, but 
this requires confirmation. 

There is a good deal of uncertainty about the 
climate of Venus. The heat there must greatly sur- 
pass heat ever felt on earth — the sun being about 
double the apparent size of our sun, and pouring out 
nearly double the amount of light and heat that we 
receive. 

This difference may be met, as already stated, by a 
sheltering, cloudy atmosphere, or the inhabitants may 
have frames and eyesight suited to the increased glare 
and warmth. 

An atmosphere and water exist there as here. 
From what we have seen above of the rapid and vio- 
lent seasons of this planet, we might think that the 
agitations of the winds, the rains, and the storms 
would surpass everything which we see and experi- 
ence here, and that its atmosphere and its seas would 
be subject to a continual evaporation and precipitation 
in torrential rains — an hypothesis confirmed by its 
light, due, doubtless, to reflection from its upper 
clouds, and to the multiplicity of the clouds them- 
selves. To judge by our own impressions, we should 
be much less pleased with this country than with our 
own, and it is even very probable that our physical 
organization, accommodating and complaisant as it is, 
could not become acclimatized to such variations of 
temperature. But it is not necessary to conclude from 



MERCURY, VENUS, AND MARS. 189 

this that Venus is uninhabitable and uninhabited. 
We may even suppose, without exaggeration, that its 
inhabitants, organized to live in the midst of these 
conditions, find themselves at their ease, like a fish in 
water, and think that our earth is too monotonous and 
too cold to serve as an abode for active and intelligent 
beings. 

Of what nature are the inhabitants of Venus? Do 
they resemble us in physical form? Are they endowed 
with an intelligence analogous to ours? Do they pass 
their life in pleasure, as Bernardin de St. Pierre said ; 
or, rather, are they so tormented by the inclemency of 
their seasons that they have no delicate perception, 
and are incapable of any scientific or artistic atten- 
tion? These are interesting questions, to which we 
have no reply. All that we can say is, that organized 
life on Venus must be little different from terrestrial 
life, and that this world is one of those which resemble 
ours most. It should, then, be inhabited by vegetable, 
animal, and human races but little different from those 
which people our planet. As to imagining it desert 
or sterile — this is an hypothesis which could not arise 
in the brain of any naturalist. The action of the di- 
vine sun must be there, as in Mercury, still more fer- 
tile than his terrestrial work, already so wonderful. 
We may add that Venus and Mercury, having been 
formed after the earth, are relatively younger than our 
planet. 

It is believed also that the axis of Venus, instead 
of being slanted only as much as the earth's axis, is 
tilted much more. Even if the tilting is less than 
some have supposed, it is probably very considerable. 



190 STORY OF THE SUN, MOON, AND STARS. 

If Venus really does "lie over" in such a manner, 
certain startling changes of climate on its surface — 
unpleasant changes, according to our ideas — would 
take place. 

Like earth, Venus would have her two arctic re- 
gions, where a burning summer's day would succeed 
a bitter winter's night, each half a year in length. 
She would have also her tropical region — only in that 
region intense cold would alternate with intense heat, 
brief seasons of each in turn. And between the trop- 
ics and the arctic regions would lie wide belts, by turns 
entirely tropical and entirely arctic. The rapidity and 
severity of these changes, following one another in a 
year about as long as eight of our months, would 
seem to be too much for any human frame to endure. 
But it all rests upon an if And we may be quite 
sure that if there are any manner of human beings 
in Venus, their frames are well suited to the climate 
of their world. 

Though Mars is one of the inner group of four 
small planets, divided by the zone of asteroids from 
the outer group of four great planets, yet he belongs 
to the outside set of Superior Planets. His orbit sur- 
rounds ours, being at all points farther off from the 
sun. Very slight "phases" have been seen in Mars. 
He turns to us, from time to time, just enough of his 
dark side to prove that he has a dark side, and that 
he does not shine like a star by his own light. But 
the phases on that planet are by no means marked as 
they are with Venus. 

Until lately it was believed that Mars possessed no 
moons. Two very small ones have, however, been 



MERCURY, VENUS, AND MARS. 19I 

lately found circling round him.* They have been 
named Deimos and Phobos, after the "sons of Mars" 
in Greek mythology. Deimos travels round Mars in 
thirty-nine hours, while Phobos performs the same 
journey in the astonishingly short period of seven 
hours and a half! 

We have here, then, a system very different from 
that of the earth and moon. But the most curious 
point is the rapidity with which the inner satellite of 




MARS AND THE PATH OF ITS SATEUJTES. 

Mars revolves round its planet. This revolution is 
performed in seven hours, thirty-nine minutes, fifteen 
seconds, although the world of Mars rotates on itself 
in twenty-four hours, thirty-seven minutes — that is to 



* The discovery of the two moons is due to the agency of a 
woman. Professor Asaph Hall, of Washington City, was searching 
by the aid of the most powerful telescope which had yet been di- 
rected to Mars, and at the very moment when the planet was in the 
most favorable condition for observation. Having searched in 
vain during several evenings in August, 1877, he was ahout to give 
up, when Mrs. Hall begged him to search a little more. He did 
so, and on the night of the nth he discovered the first of the 
satellites, and then on the 17th the second. 



1 92 STORY OF THE SUN, MOON, AND STARS. 

say, this moon turns much more quickly than the 
planet itself. This fact is inconsistent with all the 
ideas we have had up to the present on the law of 
formation of the celestial bodies. Thus, while the 
sun appears to revolve in the Martian sky in a slow 
journey of more than twenty-four hours, the inner 
moon performs its entire revolution in a third of a 
day. It follows that it rises in the west and it sets in 
the east! It passes the second moon, eclipses it from 
time to time, and goes through all its phases in eleven 
hours, each quarter not lasting even three hours. 
What a singular world! 

These satellites are quite small — they are the 
smallest celestial bodies we know. The brightness 
of the planet prevents us from measuring them ex- 
actly. It seems, however, that the nearer is the 
larger, and shows the brightness of a star of the tenth 
magnitude, and that the second shines as a star of the 
twelfth magnitude. According to the most trust- 
worthy photometric measures, the first satellite may 
have a diameter of 7.45 miles, and the second a 
diameter of 6.2 miles. The larger of these two worlds 
is scarcely larger than Paris. Should we honor 
them with the title of worlds? They are not even 
terrestrial continents, nor empires, nor kingdoms, 
nor provinces, nor departments. Alexander, Caesar, 
Charlemagne, or Napoleon, might care but little 
to receive the scepter of such worlds. Gulliver might 
juggle with them. Who knows, however? The vanity 
ot men being generally in the direct ratio of their 
mediocrity, the microscopical reasoning mites which 
doubtless swarm on their surface have also, perhaps, 



MERCURY, VENUS, AND MARS. 193 

permanent armies, which mutilate each other for the 
possession of a grain of sand. 

These two little moons received from their dis- 
coverer the names of Deimos (Terror) and P hobos 
(Flight), suggested by the two verses of Homer's 
' ' Iliad' ' which represent Mars descending on the earth 
to avenge the death of his son Ascalaphus : 

"He ordered Terror and Flight to yoke his steeds, 
And he himself put on his glittering arms." 

Phobos is the name of the nearer satellite ; Deimos, 
that of the more distant. 

The existence of these little globes had already 
been suspected from analogy, and thinkers had fre- 
quently suggested that, since the earth has one satel- 
lite, Mars should have two, Jupiter four, Saturn eight ; 
and this is indeed the fact — though as Jupiter is now 
found to have Jive satellites, this arithmetical progres- 
sion is upset. But as we experience too often in 
practice the insufficiency of these reasonings of purely 
human logic, we can not give them more value than 
they really possess. We might suppose in the same 
way now that Uranus has sixteen satellites, and Nep- 
tune thirty-two. This is possible ; but we know noth- 
ing of them, and have not even the right to consider 
this proportion as probable. It is not the less curious 
to read the following passage, written by Voltaire in 
1750 in his masterpiece, the "Micromegas:" 

" On leaving Jupiter, our travelers crossed a space 

of about a hundred millions of leagues, and reached 

the planet Mars. They saw two moons, which wait on 

this planet, and which have escaped the gaze of as- 

13 



194 STORY OF THE SUN, MOON, AND STARS. 

tronomers. I know well that Father Castel wrote 
against the existence of these two moons ; but I agree 
with those who reason from analogy. These good 
philosophers know how difficult it would be for Mars, 
which is so far from the sun, to get on with less than 
two moons. However this may be, our people found 
it so small that they feared they might not find any- 
thing to lie upon, and went on their way." 

Here we have unquestionably a very clear proph- 
ecy, a rare quality in this kind of writing. The astro- 
nomico-philosophical romance of "Micromegas" has 
been considered as an imitation of Gulliver. L,et us 
open the masterpiece of Swift himself, composed about 
1720, and we read, word for word, in Chapter III of 
the "Voyage to L,aputa:" 

" Certain astronomers . . . spend the greatest 
part of their lives in observing the celestial bodies, 
which they do by the assistance of glasses far excel- 
ling ours in goodness. For this advantage hath en- 
abled them to extend the discoveries much farther 
than our astronomers in Europe ; for they have made 
a catalogue of ten thousand fixed stars, whereas the 
largest of ours do not contain above one-third part of 
that number. They have likewise discovered two 
lesser stars, or satellites, which revolve about Mars, 
whereof the innermost is distant from the center of 
the primary planet exactly three of his diameters, and 
the outermost five. The former revolves in the space 
of ten hours, and the latter in twenty-one and a half; 
so that the squares of their periodical times are very 
near in the same proportion with the cubes of their 
distance from the center of Mars, which evidently 



MERCURY, VENUS, AND MARS. 1 95 

shows them to be governed by the same law of gravi- 
tation that influences the other heavenly bodies." 

What are we to think of this double prediction of 
the two satellites of Mars? Indeed, the prophecies 
which have been made so much of in certain doc- 
trinal arguments have not always been as clear, nor 
the coincidences so striking. However, it is evident 
that no one had ever seen these satellites before 1877, 
and that there was in this hit merely the capricious 
work of chance. We may even remark that both the 
English and French authors have only spoken ironically 
against the mathematicians, and that in 1610, Kepler, 
on receiving the news of the discovery of the satel- 
lites of Jupiter, wrote to his friend Wachenfals that 
"not only the existence of these satellites appeared to 
him probable, but that doubtless there might yet be 
found two to Mars, six or eight to Saturn, and perhaps 
one to Venus and Mercury." We can not, assuredly, 
help noticing that reasoning from analogy is here 
found on the right road. However this may be, this 
discovery truly constitutes one of the most interesting 
facts of contemporary astronomy. 

Mars is not only much smaller than th<* earth, but 
a good deal less dense in his "make." His material is 
only about three-quarters as heavy as an equal amount 
of the earth's material. A very heavy man on earth 
would be a most light and active individual on Mars. 
Gold taken from earth to Mars would weigh there no 
more than tin weighs upon earth. 

Mars has, it seems, an atmosphere, even as earth 
has. Of all the planets Mars, is the only one whose 
actual surface is discernible in the telescope. Mer- 



196 STORY OF THE SUN, MOON, AND STARS. 

cury and Venus are so hidden by dense envelopes of 
clouds that the real planets within are only now and 
then to be dimly caught sight of. Jupiter and Saturn 
are so completely enwrapped in mighty masses of 
vapor, that we can not even be certain whether there 
are any solid bodies at all inside. 

But Mars can be studied. Here and there, it is 
true, clouds sweep over the landscape, hiding from 
view for a little while one continent or another, one 
sea or another, growing, changing, melting away, as 
do the clouds of earth. Still, though these clouds 
come and go, there are other markings on the surface 
of Mars which do not change. Or, rather, they only 
change so much as the continents and oceans of earth 
would seem to vary, if watched from another planet, 
as the daily movement of earth carried them from 
west to east, or as they might be hidden for a while 
by cloud-layers coming between. It has been curi- 
ously noted that these clouds over Mars form often in 
the morning and evening, and are afterwards dis- 
persed by the heat of midday. Also there seems 
every reason to believe that rainfalls take place in 
Mars as upon earth. 

The red color of Mars is well known. This does 
not vanish in the telescope, but it is found that parts 
only have the red or orange hue, while other parts are 
dark and greenish. These are the markings which 
remain always the same, and they have been so 
closely examined that more is known about the geog- 
raphy of Mars than of any other world outside our 
own. 

Mars, at his nearest point, does not draw closer to 



MERCURY, VENUS, AND MARS. I97 

us than forty millions of miles. At such a distance 
one must not speak too confidently. There are, how- 
ever, many reasons for believing that the red portions 
are continents and that the green portions are oceans. 

The spectroscope has lately shown us that water 
does really exist in the atmosphere of Mars — unlike the 
dreary, waterless moon. So we no longer doubt that 
the cloudlike appearances are clouds, and that rain 
sometimes falls on Mars. If there is rain, and if there 
are clouds and vapor, there are probably oceans also. 

Two singular white spots are to be seen at the 
north and south poles, which we believe to be polar 
ice and snow. Somebody looking at our earth in like 
manner from a distance, would doubtless perceive two 
such white snow-spots. These two polar caps are 
seen to vary with the seasons. When the north pole 
of Mars is turned towards the sun, the white spot 
there grows smaller ; and at the same time, the south 
pole of Mars being turned away from the sun, the 
white spot there grows larger. Again, when the south 
pole is towards the sun, and the north pole away from 
the sun, the white spot at the south is seen to be the 
smallest, and the white spot at the north is seen to 
be the largest. This is exactly what takes place in 
the summers and winters of our north and south poles. 

The markings of Mars have been so carefully stud- 
ied, that at last a map has been made of the planet — 
a map of a world, never less than forty millions of 
miles away! Names have been given to the conti- 
nents and oceans — such as Dawes Continent, Herschel 
Continent, De La Rue Ocean, Airy Sea, Huggins 
Inlet, and so on. 



I98 STORY OF THE SUN, MOON, AND STARS. 

Land and water seem to be very differently ar- 
ranged on Mars from what they are on earth. Here 
we have about three times as much water as land, and 
to get from one continent to another without crossing 
the sea is in some cases impossible. But a traveler 
there might go most conveniently to and fro, hither 
and thither, to all parts of his world, either on land or 
on water, without any change. If he preferred water, 
he would never need to set foot on land; and if he 
preferred land, he would never need to enter a boat. 
The two are so curiously mingled together, narrow 
necks of land running side by side with long, narrow 
sea-inlets, that Atlantic and Pacific Oceans are un- 
known. 

Some have wondered whether the reddish color of 
the land may be caused by grass and trees being red 
instead of green. Very strange if so it were. But in 
that case, no doubt the inhabitants of Mars would 
find green just as trying to their eyesight, as we should 
find red trying to ours. 



CHAPTER XVII. 

JUPITER. 

Passing at one leap over the belt of tiny asteroids, 
about which we know little beyond their general move- 
ment, and the size and weight of a few among them, 
we reach at once the giant planet Jupiter: Mighty 
Jupiter, hurrying ever onward, with a speed, not indeed 
equal to that of Mercury or of our earth, yet eighty 
times as rapid as the speed of a cannon-ball ! Think 
of a huge body, equal in bulk to twelve hundred 
earths, equal in weight to three hundred earths, rush- 
ing ceaselessly through space, at the rate of seven 
hundred thousand miles a day! 

Jupiter's shape is greatly flattened at the poles. 
He spins rapidly on his axis, once in nearly ten hours, 
and has therefore a five hours' day and a five hours* 
night. As the slope of his axis is exceedingly slight, 
he can boast little or no changes of season. The cli- 
mate near the poles has never much of the sun's heat. 
In fact, all the year round the sun must shine upon 
Jupiter much as he shines on the earth at the equi- 
noxes. 

But the amount of light and heat received by Ju- 
piter from the sun is only about one twenty-fifth part 
of that which we receive on earth; and the sun, as 
seen from Jupiter, can have but a small, round surface, 
not even one-quarter the diameter of the sun we see 
in the sky. 

199 



200 STORY OK THE SUN, MOON, AND STARS. 

When looked at with magnifying power, the bright, 
starlike Jupiter grows into a broad, softly-shining disk 
or plate, with flattened top and bottom, and five tiny, 
bright moons close at hand. Sometimes one moon is 
on one side, and four are on the other; sometimes 




GENERAL ASPECT OF JUPITER— SATELLITE AND ITS SHADOW. 

two are one side and three on the other; sometimes 
one or more are either hidden behind Jupiter or pass- 
ing in front of him. Jupiter has also curious mark- 
ings on his surface, visible through a telescope. These 
markings often undergo changes; for Jupiter is no 
chill, fixed, dead world, such as the moon seems to be. 
There are dark belts and bright belts, usually run- 
ning in a line with the equator, from east to west. 



JUPITER. 20I 

Across the regions of the equator lies commonly a 
band of pearly white, with a dark band on either side 
of " coppery, ruddy, or even purplish" hue. Light 
and dark belts follow one after another, up to the 
north pole and down to the south pole. 

When we talk of " north and south poles" in the 
other planets, we merely mean those poles which 
point towards those portions of the starry heavens 
which we have chosen to call " northern " and "south- 
ern." You know that all the chief planets travel 
round the sun in very nearly the same plane or flat 
surface that we do ourselves. That plane is called 
the "plane of the ecliptic." Suppose that you had an 
enormous sheet of cardboard, and that in the middle 
of this cardboard the sun were fixed, half his body 
being above and half below. At a little distance, fixed 
in like manner in the card, would be the small body 
of the earth, half above and half below, her axis being 
in a slanting position. The piece of cardboard repre- 
sents what is called in the heavens the plane of the 
ecliptic — an imaginary flat surface, cutting exactly 
through the middle of the sun and of the earth. 

If the planets all traveled in the same precise plane, 
they would all be fixed in the cardboard just like the 
earth, half the body of each above and half below. 
As they do not so travel, some would have to be placed 
a little higher, some a little lower, according to what 
part of their orbits they were on. This supposed 
cardboard "plane of the ecliptic" would divide the 
heavens into two halves. One half, containing the 
constellations of the Great Bear, the Little Bear, Ce- 
pheus, Draco, and others, would be called the Northern 



203 STORY OF THE SUN, MOON, AND STARS. 

Heavens. One end of the earth's axis, pointing just 
now nearly to the Polar Star, we name the North 
Pole; and all poles of planets pointing towards this 
northern half of the heavens, are in like manner 
named by us their north poles. 

With regard to west and east, lay in imagination 
upon this cardboard plane a watch, with its face up- 
wards ; remembering that all the planets and nearly 
all the moons of the Solar System are said both to 
spin on their axes, and to travel in their orbits round 
the sun, from west to east. Note how the hands of 
your watch would move in such a position. The 
"west to east" motions of planets and moons would 
be in exactly the opposite direction from what the mo- 
tions of the watch-hands would be. 
) (To return to Jupiter. It is believed that these 
bands of color are owing to a heavy, dense atmos- 
phere, loaded with vast masses of cloudy vapor. By 
the " size " of Jupiter, we really mean the size of this 
outside envelope of clouds. ^How large the solid body 
within may be, or whether there is any such solid 
body at all, we do not know?) The extreme lightness 
of Jupiter, as compared with his great size, has caused 
strong doubts on this headA 

The white belts are supposed to be the outer side 
of cloud-masses shining in the sunlight. Travelers 
in the Alps have seen such cloud-masses, spreading 
over the whole country beneath their feet, white as 
driven snow, and shining in the sunbeams which they 
were hiding from villages below ; or looking like soft 
masses of cotton- wool, from which the mountain- 
peaks rose sharply here and there. 



JUPITER. 203 

The dark spaces between seem to be rifts or breaks 
in the clouds. Whether, when we look at those dark 
spaces, we are looking at the body of Jupiter, or only 
at lower layers of clouds, is not known. But some- 
times blacker spots show upon the dark cloud-belts, 
and this seems rather as if they were only lower lay- 
ers of clouds, the black spots giving us peeps down 
into still lower and deeper layers, or else perhaps to 
the planet itself. These appearances remind one 
strongly of the sun-spots, each with its penumbra, 
umbra, and nucleus. Occasionally bright white spots 
show, instead of dark ones. It is thought that they 
may be caused by a violent upward rush of dense 
clouds of white vapor. The white spots again recall 
the sun and hisfaculcz. 

Jupiter's bands are not fixed. Great changes go 
on constantly among them. Sometimes a white band 
will turn dark-colored, or a dark band will turn white. 
Sometimes few and sometimes many belts are to be 
seen. Sometimes a dark belt will lie slanting across 
the others, nearly from north to south. Once, in a 
single hour, an entirely new belt was seen to come 
into shape. Another time, two whole belts vanished 
in one day. The bands, in which such rapid move- 
ments are seen, are often thousands of miles in breadth. 
Sometimes these wide zones of clouds will remain for 
weeks the same. At another time a break or rift in 
them will be seen to journey swiftly over the surface 
of the planet. 

The winds on earth are often destructive. A hur- 
ricane, moving at the rate of ninety miles an hour, 
will carry away whole buildings and level entire plan- 



204 STORY OF THE SUN, MOON, AND STARS. 

tations. Such hurricanes rarely, if ever, last more 
than a few hours. But winds in Jupiter, judging from 
the movements of the clouds, often travel at the rate 
of one hundred and fifty miles an hour; and that, not 
for hours only, but for many weeks together. What 
manner of living beings could stand such weather 
may well be questioned. 
^^ (Another difficulty which arises is as to the cause 
of these tremendous disturbances on Jupiter. Our 
earthly storms are brought about by the heat of the 
sun acting on our atmosphere. But the sun-heat 
which reaches Jupiter seems very far from enough to 
raise such vast clouds of vapor, and to bring about 
such prolonged and tremendous hurricanes of wind. 

What if there is another cause ? What if Jupiter 
is not a cooled body like our earth, but a liquid, seeth- 
ing, bubbling mass of fiery heat — -just as we believe 
our earth was once upon a time, in long past ages, be- 
fore her outside crust became cold enough for men and 
animals to live thereon? The7i, indeed, we could un- 
derstand how, instead of oceans lying on his surface, 
all the water of Jupiter would be driven aloft to hang 
in masses of steam or be condensed into vast cloud- 
layers. Then we could understand why a perpetual 
stir of rushing winds should disturb the planet's at- 
mosphere. 

In that case would Jupiter be a planet at all ? Cer- 
tainly — in the sense of obeying the sun's control. Our 
earth was once, we believe, a globe of melted matter, 
glowing with heat — and farther back still, possibly, a 
globe of gas. Some people are very positive about 
these past changes ; but it is wise not to be over- 



JUPITER. 205 

positive where we can not know to a certainty what 
has taken place. ' However, Jupiter may have cooled 
down only to the liquid state, and if he goes on cooling 
he may, by and by, gain a solid crust like the earth."") 

This idea about Jupiter's hot and molten state be- 
longs quite to late years. Certain other matters seem 
to bear it out, though of actual proof we have none. 
It is thought, for instance, that the dull, coppery red 
light, showing often in the dark bands, may be a red 
glow from the heated body within. Also it has been 
calculated that Jupiter gives out much more light than 
our earth would do, if increased to his size and moved 
to his place — more, in fact, than we could reasonably 
expect him to give out. If so, whence does he obtain 
the extra brightness? If he does not shine by re- 
flected light alone, he probably shines also in some 
additional degree by his own light?} 

But what about Jupiter being inhabited ? Would 
it in such a case be quite impossible? " Impossible " 
is not a word for us to use about matters where we are 
ignorant. We can only say that it is impossible for 
us to imagine any kind of living creatures finding a 
home there, if our present notions about the present 
state of Jupiter are correct. Then is the chief planet 
of the Solar System a huge, useless monument of 
God's power to create? Not so fast. Even as merely 
such a monument, he could not be useless. And 
even if he were put to no present use at all, it might 
be merely because this is a time of preparation for 
the future. God has his times of long and slow 
preparation, alike with worlds, with nations, and 
with individuals. 



206 STORY OP THE SUN, MOON, AND STARS. 

But now as to the five moons circling round Ju- 
piter. There used to be some very pretty ideas afloat 
about the wonderful beauty of the moons, as seen 
from Jupiter, their united brilliancy so far surpassing 
the shining of our one poor satellite, and making up 
for the dim light of Jupiter's sun. 

A certain little difficulty was not quite enough con- 
sidered. If anybody were living on the surface of Ju- 
piter, he would have, one is inclined to think, small 




SATEUJTES OF JUPITER COMPARED WITH THE EARTH AND MOON. 

chance of often seeing the moons through the cloud- 
laden atmosphere. 

The nearest of the tour larger moons to Jupiter 
would, it is true, appear — when visible at all — rather 
bigger than ours does to us; while the two next would 
be almost half as large, and the farthest about a quarter 
as large — supposing inhabitants of Jupiter to have 
our powers of vision. 

All taken together they would cover a considerably 
larger space in the sky than does our moon. But it 
must be remembered that Jupiter's moons, like ours, 
shine merely by reflected sunlight. And so dim is the 



JUPITER. 207 

sunshine at that distance compared with what it is 
at our distance, that all the five moons together, even 
if full at the same time, could only give about one- 
sixteenth part of the light which we obtain from our 
one full moon. 

Besides, they never are full together, seen from any 
one part of Jupiter. The four inner moons are never 
to be seen "full" at all ; for just when they might be 
so, they are eclipsed or shaded by Jupiter's shadow. 
The fourth sometimes escapes this eclipse, from being 
so much farther away. 

A thought has been lately put forward, which may 
or may not have truth in it. What if — instead of 
Jupiter being a world, inhabited by animals and peo- 
ple, as is often supposed, with a small distant sun and 
five dim moons to give them light — what if Jupiter is 
himself in some sort a second sun to his moons, and 
what if those "moons" are really inhabited planets? 
It may be so. That is all we can say. The idea is 
not an impossible one. 

The so-called "moims" are certainly small. But 
they are by no means too small for such a purpose. 
Jupiter would in that case, with his five moons circling 
round him, enjoying his light and warmth, be a small 
picture of the sun, with his four inner planets and the 
asteroids circling round him, basking in a more lavish 
amount of the same. 

Picturing the moons as giving light to Jupiter, we 
find them seemingly dim and weak for such a pur- 
pose — though, of course, we may here make a grand 
mistake in supposing the eyesight of living creatures 
in Jupiter to be no better than our own eyesight. 



2o8 STORY OF THE SUN, MOON, AND STARS. 

Even upon earth a cat can see plainly where a man 
has to grope his way in darkness. 

But by picturing the moons as inhabited, and 
Jupiter as giving out some measure of heat and light 




THE SYSTEM OF JUPITER. 

to make up for the lessened amount of light and heat 
received from the sun, the matter becomes more easy 
to our understanding. 

The nearest moon has indeed a magnificent view 
of Jupiter as a huge bright disk in its sky, no less 



JUPITER. 209 

than three thousand times as large as our moon ap- 
pears to us, shining brightly with reflected sunlight, 
and it may be glowing with a red light of his own in 
addition. Even the farthest off of the five sees him 
with a face sixty-five times the size of our moon. 
And the varying colors and stormy changes in the 
cloud-belts, viewed thus near at hand, must afford 
marvelously beautiful effects. 

Just as Mercury, Venus, Earth, and Mars travel 
round the sun, at different distances, nearly in the 
same plane, so Jupiter's five moons travel round him, 
at different distances, nearly in the same plane. 
Jupiter's moons are always to be seen in a line, not 
one high and another low, one near his pole and an- 
other near his equator. 

The moon nearest to Jupiter, discovered in Sep- 
tember, 1892, by Professor Barnard, now of the Yerkes 
Observatory of the Chicago University, has a probable 
diameter of one hundred miles, and revolves round its 
primary in about twelve hours. The second satellite, 
named Io, is said to be over two thousand miles in 
diameter, travels round Jupiter in less than two of our 
days, and is eclipsed by Jupiter's shadow once in every 
forty-two hours. 

The third moon, Europa, is rather smaller, takes 
over three days to its journey, and suffers eclipse once 
in every eighty-five hours. 

The fourth moon, Ganymede, is believed to be con- 
siderably larger than Mercury, journeys round Jupiter 
once a week, and is eclipsed once every hundred and 
seventy-one hours. 

The fifth moon, Callisto, is also said to be slightly 
14 



2IO STORY OF THE SUN, MOON, AND STARS. 

larger than Mercury, performs its journey in some- 
thing more than sixteen days, and from its greater 
distance suffers eclipse less often than the other four. 

The distance of the nearest is more than one hun- 
dred thousand miles from Jupiter ; that of the farthest, 
more than one million miles. 

The following table presents more minutely the 
results of the latest discoveries concerning these sat- 
ellites : 



SATELLITES. 


DISTANCE FROM 
CENTER OF 

JUPITER. 


DIAMETER. 


PERIOD OF 

REVOLUTION. 


1. Barnard's Satellite, 

2. IO, 

3. Europa, 

4. Ganymede 

5. Callisto, 


112,500 miles. 
266,000 " 
424,000 " 
676,000 " 
1,189,000 " 


100 miles. 
2,356 " 
2,046 « 
3,596 " 

2,728 « 


D. H. M. S. 

11 57 23 

1 18 27 33 

3 13 13 42 

7 3 42 33 

16 15 32 11 



The fact of these eclipses, and of the shadow 
thrown by Jupiter's body, shows plainly that though 
he may give out some measure of light, as has been 
suggested, yet that light can not be strong, or it 
would prevent any shadow from being thrown by the 
sunlight. Also, the dense masses of cloud around 
him, though reflecting sunlight brightly, would shut 
in much of his own light. Possibly it is chiefly as 
heat-giver and as sunlight-reflector that Jupiter serves 
his five satellites. 

As with our own moon, so with Jupiter's moons, 
the real center of their orbit is the sun, and not 
Jupiter. They accompany Jupiter in his journey, 
controlled by the sun, and immensely influenced by 
Jupiter. 



JUPITER. 211 

At night the spectacle of the sky seen from Ju- 
piter is, with reference to the constellations, the same 
as that which we see from the earth. There, as here, 
shine Orion, the Great Bear, Pegasus, Andromeda, 
Gemini, and all the other constellations, as well as the 
diamonds of our sky: Sirius, Vega, Capella, Procyon, 
Rigel, and their rivals. The 390,000,000 of miles 
which separate us from Jupiter in no way alter the 
celestial perspectives. But the most curious char- 
acter of this sky is unquestionably the spectacle of the 
five moons, each of which shows a different motion. 
The second moves in the firmament with an enor- 
mous velocity, and Barnard's satellite still faster, and 
produce almost every day total eclipses of the sun in 
the equatorial regions. The four inner moons are 
eclipsed at each revolution, just at the hours when they 
are at their "full." The fifth alone attains the full 
phase. 

Contrary to the generally received opinion, these 
bodies do not give to Jupiter all the light which is 
supposed. We might think, in fact, as has been so 
often stated, that these five moons illuminate the 
nights five times better relatively than our single 
moon does in this respect, and that they supplement in 
some measure the feebleness of the light received 
from the sun. This result would be, assuredly, very 
agreeable, but nature has not so arranged it. The 
five satellites cover, it is true, an area of the sky 
greater than our moon, but they reflect the light of a 
sun twenty-seven times smaller than ours ; indeed, the 
total light reflected is only equal to a sixteenth of 
that of our full moon, even supposing the soil of these 



212 STORY OF THE SUN, MOON, AND STARS. 

satellites to be as white as it appears to be, especially 
the fifth satellite. 

Jupiter appears to be a world still in process of 
formation, which lately — some thousands of centuries 
ago — served as a sun to his own system of five or 
perhaps more worlds. If the central body is not at 
present inhabited, his satellites may be. In this case, 
the magnificence of the spectacle presented by Jupiter 
himself to the inhabitants of the satellites is worthy 
of our attention. Seen from Barnard's satellite, Ju- 
piter's disk has a diameter of 47 , or more than half 
the distance from the horizon to the zenith. Seen 
from the second satellite, the Jovian globe presents an 
immense disk of twenty degrees in diameter, or 1,400 
times larger than the full moon! What a body! 
What a picture, with its belts, its cloud motions, and 
its glowing coloration, seen from so near! What a 
nocturnal sun ! — still warm, perhaps. Add to this the 
aspect of the satellites themselves seen from each other, 
and you have a spectacle of which no terrestrial night 
can give an idea. 

Such is the world of Jupiter from the double point 
of view of its vital organization and of the spectacle 
of external nature, seen from this immense observa- 
tory. 

The attraction of the planets has always played an 
important part in the motion of comets and the form 
of their orbits. The enormous size of Jupiter gives 
it more influence than any other planet, and we are 
not surprised that it should have seriously interfered 
with some of the comets that belong to the Solar 
System. We have already seen that Biela's comet 



JUPITER. 



213 



was captured by Jupiter, and that it was probably dis- 
solved into meteoric dust. We show in the cut the 
orbits of eight others that circle around the sun, but 
retreat no farther away than Jupiter. These are the 




ORBITS OF NINE COMETS CAPTURED BY JUPITER. 

orbits as now determined, but they vary from age to 
age on account of disturbances of other planets. But 
it is not likely that the comets themselves will ever 
escape from the control of Jupiter. 



CHAPTER XVIII. 

SATURN. 

The system of Jupiter is a simple system compared 
with that of Saturn, next in order. For whereas 
Jupiter has only five moons, Saturn has eight, and, 
in addition to these, he has three wonderful rings. 
Neither rings nor moons can be seen without a tele- 
scope, on account of Saturn's great distance from us — 
more than three thousand times the distance of the 
moon, or upwards of eight hundred millions of miles, 
Saturn's mean distance from the sun is eight hundred 
and seventy-six million seven hundred and sixty-seven 
thousand miles. 

Saturn does not equal his mighty brother Jupiter 
in size, though he comes near enough in this respect 
to be called often his "twin" — just as that small pair 
of worlds, Venus and Earth, are called "twins." 
While Jupiter is equal in size to over one thousand 
two hundred earths, Saturn is equal to about seven 
hundred earths. And while Jupiter is equal in weight 
to three hundred earths, Saturn is only equal in weight 
to ninety earths. He appears to be made of very light 
materials — not more than three-quarters as dense as 
water. This would show the present state of Saturn 
to be very different from the present state of the earth. 
We are under the same uncertainty in speaking of 
Saturn as in speaking of Jupiter. Like Jupiter, Saturn 
is covered with dense masses of varying clouds, occa- 

214 



SATURN. 



215 



sionally opening and allowing the astronomer peeps 
into lower cloud-levels ; but rarely or never permitting 
the actual body of the planet to be seen. 

The same perplexities also come in here, to be an- 
swered much in the same manner. We should cer- 
tainly expect that in a vast globe like Saturn the 
strong force of attraction would bind the whole into a 




SATURN AND THE EARTH — COMPARATIVE SIZE. 

dense solid mass; instead of which, Saturn is about 
the least solid of all the planets. He seems to be 
made up of a light, watery substance, surrounded by 
vapor. 

One explanation can be offered. What if the globe 
of Saturn be still in a red-hot, molten state, keeping 
such water as would otherwise lie in oceans on his 
surface, floating aloft in masses of steam, the outer 
parts of which condense into clouds? 

No one supposes that Jupiter and Saturn are in the 
same condition of fierce and tempestuous heat as the 



2l6 STORY OF THB SUN, MOON, AND STARS. 

sun. They may have been so once, but they must 
now have cooled down very many stages from that 
condition. Though no longer, however, a mass of 
far-reaching flames and fiery cyclones, the body of 
each may have only so far cooled as to have reached a 
stage of glowing molten red-heat, keeping all water in 
the form of vapor, and sending up strong rushes of 
burning air to cause the hurricanes which sweep to 
and fro the vast cloud-masses overhead. 

And if this be the case, then, with Saturn as with 
Jupiter, comes the question, Can Saturn be inhabited? 
And if — though we may not say it is impossible, yet 
we feel it to be utterly unlikely — then again follows 
the question, What if Saturn's moons are inhabited? 

Telescopic observations tempt us to believe that 
there is on this planet a quantity of heat greater than 
that which results from its distance from the sun; for 
the day-star as seen from Saturn is, as we have said, 
ninety times smaller in surface, and its heat and light 
are reduced in the same proportion. Water could 
only exist in the solid state of ice, and the vapor of 
water could not be produced so as to form clouds 
similar to ours. Now, meteorological variations are 
observed similar to those which we have noticed on 
Jupiter, but less intense. Facts, then, combine with 
theory to show us that the world of Saturn is at a 
temperature at least as high as ours, if not higher. 

But the strangest feature of the Saturnian calendar 
is, unquestionably, its being complicated, not only 
with the fabulous number of 25,060 days in a year, 
but, further, with eight different kinds of months, of 
which the length varies from 22 hours to 79 days — 



SATURN. 217 

that is to say, from about two Saturnian days to 167. 
It is as if we had here eight moons revolving in eight 
different periods. 

The inhabitants of such a world must assuredly 
differ strangely from us from all points of view. 
The specific lightness of the Saturnian substances 
and the density of the atmosphere will have con- 
ducted the vital organization in an extra-terrestrial 
direction, and the manifestations of life will be pro- 
duced and developed under unimaginable forms. To 
suppose that there is nothing fixed, that the planet it- 
self is but a skeleton, that the surface is liquid, that 
the living beings are gelatinous — in a word, that all is 
unstable — would be to surpass the limits of scientific 
induction. 

The diameter of the largest moon is about half the 
diameter of the earth, or much larger than Mercury. 
The four inner satellites are all nearer to Saturn than 
our moon to us, though the most distant of the eight 
is ten times as far away. The inner moon takes less 
than twenty-three hours to travel round Saturn, and 
the outer one over seventy-nine days. 

A great many charming descriptions have been 
worked up, with Saturn as with Jupiter, respecting 
the magnificent appearance of the eight radiant 
moons, joined to the glorious shining of the rings, 
as quite making up for the diminished light and heat 
of the sun. But here again comes in the doubt, 
whether really it is the moons who make up to Saturn 
for lack of light, or whether it is Saturn who makes 
up to the moons for lack of light. 

Certainly, Saturn's cloudy covering would a little 



2l8 STORY OF THE SUN, MOON, AND STARS. 

interfere with observations of the moons by any in- 
habitants of the solid body within — supposing there 
be any solid body at all. And though it sounds very 
wonderful to have eight moons instead of one moon, 
yet all the eight together give Saturn only a very 
small part of the light which we receive from our 
one full moon — so much more dimly does the sun light 
them up at that enormous distance. 

The same thing has been noticed with Saturn as 
with Jupiter — that he seems to shine more brightly 
than is to be expected in his position, from mere re- 
flection of the sun's rays. A glowing body within, 
sending a certain amount of added light through or 
between the masses of clouds, would explain av/ay 
this difficulty. 

One more possible proof of Saturn's half-liquid 
state is to be found in his occasional very odd changes 
of shape. Astronomers have been startled by a pe- 
culiar bulging out on one side, taking off from his 
roundness, and giving a square-shouldered aspect. 
We may not say it is quite impossible that a solid 
globe should undergo such tremendous upheavals and 
outbursts as to raise a great portion of its surface five 
or six hundred miles above the usual level — the 
change being visible at a distance of eight hundred 
millions of miles. But it would be easier to under- 
stand the possibility of such an event, in the case 
of a liquid, seething mass, than in the case of a 
solid ball. 

On the other hand this alteration of outline may 
be caused simply by a great upheaval not of the plan- 
et's surface, but of the overhanging layers of clouds. 



SATURN. 219 

Some such changes, only much slighter, have been 
remarked in Jupiter. 

And now as to the rings. Nothing like them is to 
be seen elsewhere in the Solar System. They are be- 
lieved to be three in number; though some would 
divide them into more than three. Passing com- 
pletely round the whole body of Saturn, they rise, one 
beyond another, to a height of many thousands of miles. 

The inner edge of the inner ring — an edge perhaps 
one hundred miles in thickness — is more than ten 
thousand miles from the surface of Saturn or more 
strictly speaking, from the outer surface of Sat- 
urn's cloudy envelope. A man standing exactly on 
the equator and looking up, even if no clouds came 
between, would scarcely be able to see such a slender 
dark line at such a height. 

This dark, transparent ring, described sometimes 
as dusky, sometimes as richly purple, rises upwards 
to a height or breadth of nine thousand miles. Closely 
following it is a ring more brilliant than Saturn himself, 
over eighteen thousand miles in breadth. When as- 
tronomers talk of the "breadth " of these rings, it 
must be understood that they mean the width of the 
band measured upwards, in a direction away from the 
planet. 

Beyond the broad, bright ring is a gap of about 
one thousand seven hundred miles. Then follows the 
third ring, ten thousand miles in breadth ; its outer- 
most edge being at a height of more than forty-eight 
thousand miles from Saturn. The color of the third 
ring is grayish, much like the gray markings often 
seen on Saturn. 



220 STORY OF THE SUN, MOON, AND STARS. 

What would not be our admiration, our astonish- 
ment, our stupor perhaps, if it were granted us to be 
transported there alive, and, among all these extra- 
terrestrial spectacles, to contemplate the strange as- 
pect of the rings, which stretch across the sky like a 
bridge suspended in the heights of the firmament! 
Suppose we lived on the Saturn ian equator itself, 
these rings would appear to us as a thin line drawn 
across the sky above our heads, and passing exactly 
through the zenith, rising from the east and increas- 
ing in width, then descending to the west and dimin- 
ishing according to perspective. Only there have we 
the rings precisely in the zenith. The traveler who 
journeys from the equator towards either pole leaves 
the plane of the rings, and these sink imperceptibly, 
at the same time that the two extremities cease to ap- 
pear diametrically opposite, and by degrees approach 
each other. What an amazing effect would be pro- 
duced by this gigantic arch, which springs from the 
horizon and spans the sky ! The celestial arch dimin- 
ishes in height as we approach the pole. When we 
reach the sixty-third degree of latitude the summit of 
the arch has descended to the level of our horizon and 
the marvelous system disappears from the sky; so that 
the inhabitants of those regions know nothing of it, 
and find themselves in a less favorable position to 
study their own world than we, who are nearly 800,- 
000,000 miles distant. 

During one-half of the Saturnian year the rings 
afford an admirable moonlight on one hemisphere of 
the planet, and during the other half they illuminate 
the other hemisphere ; but there is always a half-year 



SATURN. 221 

without " ringlight," since the sun illuminates but one 
face at a time. Notwithstanding their volume and 
number, the satellites do not give as much nocturnal 
light as might be supposed; for they receive, on an 
equal surface, only the ninetieth part of the solar 
light which our moon receives. All the Saturnian sat- 
ellites which can be at the same time above the hor- 
izon and as near as possible to the full phase do not 
afford more than the hundredth part of our lunar light. 
But the result may be nearly the same, for the optic 
nerve of the Saturnians may be ninety times more 
sensitive than ours. 

But there are further strange features in this system. 
The rings are so wide that their shadow extends over 
the greater part of the mean latitudes. During fifteen 
years the sun is to the south of the rings, and for fif- 
teen years it is to the north. The countries of Sat- 
urn's world which have the latitude of Paris endure 
this shadow for more than five years. At the equator 
the eclipse is shorter, and is only renewed every fifteen 
years; but there are every night, so to say, eclipses 
of the Saturnian moons by the rings and by them- 
selves. In the circumpolar regions the day-star is 
never eclipsed by the rings ; but the satellites revolve 
in a spiral, describing fantastic rounds, and the sun 
himself disappears at the pole during a long night of 
fifteen years. 

At one time it was supposed that the rings were 
solid, but they are now believed to consist of countless 
myriads of meteorites, each whirling in its own ap- 
pointed pathway round the monster planet. 

As already said — leaving out of the question the 



222 STORY OF THE SUN, MOON, AND STARS. 

cloudy atmosphere — a man standing on the equator 
would see nothing of the rings. A man standing at 
the north pole or the south pole of Saturn could see 
nothing either, since the rings would all lie below his 
horizon. But if he traveled southward from the north 



IDEAI, VIEW OF SATURN'S RINGS AND SATElyUTES FROM THE 
PLANET. 

pole, or northward from the south pole, towards the 
equator, he would in time see the ringed arch ap- 
pearing above the horizon, rising higher and growing 
wider with every mile of his journey ; and when he 
was in a position to view the whole broad expanse, the 
transparent half-dark belt below, the wide radiant band 



SATURN. 223 

rising upwards over that, and the grayish border sur- 
mounting all, he would truly have a magnificent spec- 
tacle before him. 

This magnificent spectacle is, however, by no means 
always visible, even from those parts of Saturn where 
alone it ever can be seen. The rings shine merely 
by reflected sunlight. Necessarily, therefore, while 
the sunbeams make one side bright the other side is 
dark ; and not only this, but the rings throw broad and 
heavy shadows upon Saturn in the direction away 
from the sunlight. 

In the daytime they probably give out a faint shin- 
ing, something like our own moon when seen in sun- 
light. During the summer nights they shine, no 
doubt, very beautifully. During the winter nights it 
so happens that their bright side is turned away ; and 
not only that, but during the winter days the rings, 
while giving no light themselves to the wintry hem- 
isphere of Saturn, completely hide the sun. 

When it is remembered that Saturn's winter — that 
is, the winter of each hemisphere in turn — lasts dur- 
ing fifteen of our years; and when we hear of total 
eclipses of the sun lasting unbroken through eight 
years of such a winter, with not even bright rings to 
make up for his absence, we can not think of Sat- 
urn as a tempting residence. The sun gives Saturn 
at his best only about one-ninetieth of the heat and 
light that he gives to our earth ; but to be deprived of 
even that little for eight years at a time, does indeed 
sound somewhat melancholy. 

Looking now at the other side of the question, the 
possible inhabitants of the moons, especially those 



224 STORY OF THE) SUN, MOON, AND STARS. 

near at hand, would have splendid views of Saturn 
and his rings in all their varying phases. For Saturn 
is a beautiful globe, wrapped in his changeful envel- 
ope of clouds, which, seen through a telescope, are lit 
up often with rainbow tints of blue and gold ; a creamy 
white belt lying usually on the equator; while around 
extend the purple and shining and gray rings, some- 
times rivaling in bright colors Saturn himself. 

We are compelled to assume that the continuous 
appearance of the rings is not due to real continuity 
of substance, but that they are composed of flights of 
disconnected satellites, so small and so closely packed 
that, at the immense distance to which Saturn is re- 
moved, they appear to form a continuous mass. There 
are analogous instances in the Solar System. In the 
zone of asteroids we have an undoubted instance 
of a flight of disconnected bodies traveling in a ring 
about a central attracting mass. The existence of 
zones of meteorites traveling around the sun has long 
been accepted as the only probable explanation of the 
periodic returns of meteoric showers. Again, the sin- 
gular phenomenon called the Zodiacal Light is, in all 
probability, caused by a ring of minute cosmical bodies 
surrounding the sun. In the Milky Way and in the 
ring-nebulae we have other illustrations of similar ar- 
rangements in nature, belonging, however, to orders 
immeasurably vaster than any within the Solar Sys- 
tem. 

The moons of Saturn do not, like those of Jupiter, 
travel in one plane. 



CHAPTER XIX. 

URANUS AND NEPTUNE. 

Tiiviv the year 1781, Saturn was believed to be the 
outermost planet of the Solar System, and nobody 
suspected the fact of two great, lonely brother-planets 
wandering around the same sun at vast distances be- 
yond, — Uranus, nine hundred millions of miles from 
Saturn; Neptune, nine hundred millions of miles 
from Uranus. No wonder they remained long undis- 
covered. 

Uranus can sometimes be seen by the unaided eye 
as a dim star of the sixth magnitude. And when he 
was known for a planet, it was found that he had 
been often so seen and noted. Again and again he 
had been taken for a fixed star, and as he moved on, 
disappearing from that particular spot, it was sup- 
posed that the star had vanished, 

One night, March 13, 1781, when William Her- 
schel was busily exploring the heavens with a powerful 
telescope, he noticed something which he took for a 
comet without a tail. He saw it was no mere point of 
light like the stars, but had a tiny round disk or face, 
which could be magnified. So he watched it care- 
fully, and found in the course of a few nights that it 
moved — very slowly, certainly; but still it did move. 
Further watching and calculation made it clear that, 
though the newly-found heavenly body was at a very 
great distance from the sun, yet it was moving slowly 
15 225 



226 STORY OP THE SUN, MOON, AND STARS. 

in an orbit round the sun. Then it was known to be 
a planet, and another member of the Solar System. 

From that day the reputation of Herschel rapidly 
increased. King George III, who loved the sciences 
and patronized them, had the astronomer presented 
to him ; charmed with the simple and modest account 
of his efforts and his labors, he secured him a life 
pension and a residence at Slough, in the neighbor- 
hood of Windsor Castle. His sister Caroline assisted 
him as secretary, copied all his observations, and 
made all his calculations ; the king gave him the title 
and salary of assistant astronomer. Before long the 
observatory at Slough surpassed in celebrity the prin- 
cipal observatories of Europe ; we may say that, in 
the whole world, this is the place where the most dis- 
coveries have been made. 

Astronomers soon applied themselves to the ob- 
servation of the new body. They supposed that this 
"comet" would describe, as usually happens, a very 
elongated ellipse, and that it would approach consid- 
erably to the sun at its perihelion. But all the calcu- 
lations made on this supposition had to be constantly 
recommenced. They could never succeed in represent- 
ing all its positions, although the star moved very 
slowly: the observations of one month would utterly 
upset the calculations of the preceding month. 

Several months elapsed without a suspicion that a 
veritable planet was under observation, and it was not 
till after recognizing that all the imaginary orbits for 
the supposed comet were contradicted by the observa- 
tions, and that it had probably a circular orbit much 
farther from the sun than Saturn, till then the fron- 




Prominent Astronomers of Former Times. 



228 STORY OF THE SUN, MOON, AND STARS. 

tier of the system, that astronomers came to consider 
it as a planet. Still, this was at first bnt a provisional 
consent. 

It was, in fact, more difficult than we may think to 
increase without scruple the family of the sun. In- 
deed, for reasons of expediency this idea was op- 
posed. Ancient ideas are tyrannical. Men had so 
long been accustomed to consider old Saturn as the 
guardian of the frontiers, that it required a rare bold- 
ness of spirit to decide on extending these frontiers 
and marking them by a new world. 

William Herschel proposed the name of Georgium 
Sidus " the Star of George," just as Galileo had given 
the name of " Medicean stars " to the satellites of Ju- 
piter discovered by him, and as Horace had said Julium 
Sidus. Others proposed the name of Neptune, in 
order to maintain the mythological character, and to 
give to the new body the trident of the English mari- 
time power ; others, Uranus, the most ancient deity of 
all, and the father of Saturn, to whom reparation was 
due for so many centuries of neglect. L,alande pro- 
posed the name of Herschel, to immortalize the name 
of its discoverer. These last two denominations pre- 
vailed. For a long time the planet bore the name of 
Herschel ; but custom has since declared for the myth- 
ological appellation, and Jupiter, Saturn, and Uranus 
succeed each other in order of descent — son, father, 
and grandfather. 

The discovery of Uranus extended the radius of 
the Solar System from 885,000,000 to 1,765,000,000 
of miles. 

The apparent brightness of this planet is that of 



URANUS AND NEPTUNE. 229 

a star of the sixth magnitude ; observers whose sight 
is very piercing may succeed in recognizing it with 
the naked eye when they know where to look for it. 
Uranus moves slowly from west to east, and takes no 
less than eighty-four years to make the complete cir- 
cuit of the sky. In its annual motion round the sun 
the earth passes between the sun and Uranus every 
369 days — that is to say, once in a year and four days. 
It is at these times that this planet crosses the merid- 
ian at midnight. We can observe it in the evening 
sky for about six months of every year. 

Everybody supposed that now, at least, the outer- 
most member of all was discovered. But a very 
strange and remarkable thing happened. 

Astronomers know with great exactness the paths 
of the planets in the heavens. They can tell, years 
beforehand, precisely what spot in space will be filled 
at any particular time by any particular planet. I am 
speaking now of their movements round the sun and 
in the Solar System — not of the movements of the 
whole family with the sun, about which little is yet 
known. 

Each planet has its own particular pathway; its 
own particular distance from the sun, varying at each 
part of its pathway ; its own particular speed in trav- 
eling round the sun, changing constantly from faster 
to slower or slower to faster, according to its distance 
from the sun, and according to the pull backwards or 
forwards of our neighboring planets in front or in rear. 
For as the orbits of all the planets are ovals, with the 
sun not in the middle, but somewhat to one side of the 
middle, it follows that all the planets, in the course of 



230 STORY OF THE SUN, MOON, AND STARS. 

their years, are sometimes nearer to and sometimes 
farther from the sun. 

The astronomers of the present day understand 
this well, and can describe with exactness the path- 
way of each planet. This knowledge does not come 
merely from watching one year how the planets travel, 
and remembering for another year, but is much more 
a matter of close and difficult calculation. Many 
things have to be considered, such as the planet's 
distance from the sun, the sun's power of attraction, 
the planet's speed, the nearness and weight of other 
neighboring planets. 

All these questions were gone into, and astronomers 
sketched out the pathway in the heavens which they 
expected Uranus to follow. He would move in such 
and such an orbit, at such and such distances from the 
sun, and at such and such rates of speed. 

But Uranus would not keep to these rules. He 
quite discomfited the astronomers. Sometimes he 
went fast, when, according to their notions, he ought 
to have gone more slowly; and sometimes he went 
slowly, when they would have looked for him to go 
more fast, and the line of his orbit was quite outside 
the line of the orbit which they had laid down. He 
was altogether a perplexing acquaintance, and diffi- 
cult to understand. However, astronomers felt sure 
of their rules and modes of calculation, often before 
tested, and not found to fail. They made a guess at 
an explanation. What if there were yet another 
planet beyond Uranus, disturbing his motions — now 
drawing him on, now dragging him back, now so far 
balancing the sun's attraction by pulling in the oppo- 



URANUS AND NEPTUNE. 23 1 

site direction as to increase the distance of Uranus 
from the sun? 

It might be so. But who could prove it? Hun- 
dreds of years might pass before any astronomer, in 
his star-gazing, should happen to light upon such a 
dim and distant world. Nay, the supposed planet 
might be, like Uranus, actually seen, and only be mis- 
taken for a "variable star," shining but to disappear. 

There the matter seemed likely to rest. There the 
matter probably would have rested for a good while, 
had not two men set themselves to conquer the diffi- 
culty. One was a young Englishman, a student of 
Cambridge, John Couch Adams ; the other, a young 
Frenchman, Urbain Jean Joseph Leverrier, — both be- 
ing astronomers. 

Each worked independently of the other, neither 
knowing of the other's toil. The task which they 
had undertaken was no light one — that of reaching 
out into the unknown depths of space to find an un- 
known planet. 

Each of these silent searchers into the sky-depths 
calculated what the orbit and speed of Uranus would 
be, without the presence of another disturbing planet 
beyond. Each examined what the amount of disturb- 
ance was, and considered the degree of attraction 
needful to produce that disturbance, together with 
the direction from which it had come. Each, in 
short, gradually worked his way through calculations 
far too deep and difficult for ordinary minds to grasp, 
till he had found just that spot in the heavens where a 
planet ought to be, to cause, according to known laws, 
just such an effect upon Uranus as had been observed. 



232 STORY OF THE SUN, MOON, AND STARS. 

Adams finished his calculation first, and sent the 
result to two different observatories. Unfortunately, 
his report was not eagerly taken up. It was, in fact, 
hardly believed. L,everrier finished his calculation 
also, and sent the result to the Berlin Observatory. 
The planet was actually seen in England first, but the 
discovery was actually made known from Berlin first. 
The young Englishman had been beforehand, but the 
young Frenchman gained foremost honor. 

It was on the 23d of September, 1846, that Le- 
verrier's letter reached the Berlin astronomers. The 
sky that night was clear, and we can easily understand 
with what anxiety Dr. Galle directed his telescope to 
the heavens. The instrument was pointed in accord- 
ance with Leverrier's instructions. The field of view 
showed, as does every part of the heavens, a multi- 
tude of stars. One of these was really the planet. 
The new chart — prepared by the Berlin Academy of 
Sciences, upon which the place of every star, down 
even to those of the tenth magnitude, was engraved — 
was unrolled, and, star by star, the heavens were com- 
pared with the chart. As the process of identification 
went on, one object after another was found in the 
heavens as engraved on the chart, and was of course 
rejected. At length a star of the eighth magnitude — 
a brilliant object — was brought into review. The 
map was examined, but there was no star there. 
This object could not have been in its present place 
when the map was formed. The object was there- 
fore a wanderer — a planet. Yet it is necessary to be 
excessively cautious in such a matter. 

Many possibilities had to be guarded against. It 



URANUS AND NEPTUNE. 233 

was, for instance, possible that the object was really a 
star which, by some mischance, elnded the carefhl eye 
of the astronomer who constrncted the map. It was 
even possible that the star might be one of the large 
class of variables which alternate in brightness, and 
it might have been conceivable that it was too faint 
to be seen when the chart was made. Even if neither 
of these explanations would answer, it was still neces- 
sary to show that the object was now moving, and 
moving with that particular velocity and in that par- 
ticular direction which the theory of Leverrier indi- 
cated. The lapse of a single day was sufficient to 
dissipate all doubts. The next night the object was 
again observed. It had moved, and when its motion 
was measured it was found to accord precisely with 
what Leverrier had foretold. Indeed, as if no circum- 
stance in the confirmation should be wanting, it was 
ascertained that the diameter of the planet, as meas- 
ured by the micrometers at Berlin, was practically co- 
incident with that anticipated by Leverrier. 

The world speedily rang with the news of this 
splendid achievement. Instantly the name of Lever- 
rier rose to a pinnacle hardly surpassed by that of any 
astronomer of any age or country. For a moment it 
seemed as if the French nation were to enjoy the un- 
divided honor of this splendid triumph. But in the 
midst of the paeans of triumph with which the en- 
thusiastic French nation hailed the discovery of Le- 
verrier, there appeared a letter from Sir John Herschel 
in the Athenceum for 3d October, 1846, in which he 
announced the researches made by Adams, and claimed 
for him a participation in the glory of the discovery. 



234 STORY OF THE) SUN, MOON, AND STARS. 

Subsequent inquiry has shown that this claim was a 
just one, and it is now universally admitted by all in- 
dependent authorities. 

This, however, was of slight comparative impor- 
tance. The truly wonderful part of the matter was, 
that these two men could have so reasoned that, from 
the movements of one lately-discovered planet, they 
could point out the exact spot where a yet more dis- 
tant planet ought to be, and that close to this very 
spot the planet was found. For when, both in Eng- 
land and in Germany, powerful telescopes were pointed 
in the direction named — there the planet was. No 
doubt about the matter. Not a star, but a real new 
planet in the far distance, wandering slowly round 
the sun. 

Here we have the discovery of Neptune in its sim- 
ple grandeur. This discovery is splendid, and of the 
highest order from a philosophical point of view, for 
it proves the security and the precision of the data of 
modern astronomy. Considered from the point of 
view of practical astronomy, it was but a simple exer- 
cise of calculation, and the most eminent astronomers 
saw in it nothing else ! It was only after its verifica- 
tion, its public demonstration — it was only after the 
visual discovery of Neptune — that they had their eyes 
opened, and felt for a moment the dizziness of the in- 
finite in view of the horizon revealed by the Neptu- 
nian perspective. The author of the calculation him- 
self, the transcendent mathematician, did not even 
give himself the trouble to take a telescope and look 
at the sky to see whether a planet was really there ! 
I even believe that he never saw it. For him, how- 



URANUS AND NEPTUNE. 235 

ever, then and always, to the end of his life, astronomy 
was entirely inclosed in formulae — the stars were but 
centers of force. 

Very often I submitted to him the doubts of an 
anxious mind on the great problems of infinitude : I 
asked him if he thought that the other planets might 
be inhabited like ours, what might be especially the 
strange vital conditions of a world separated from the 
sun by the distance of Neptune, what might be the 
retinue of innumerable suns scattered in immensity, 
what astonishing colored lights the double stars should 
shed on the unknown planets which gravitate in these 
distant systems. His replies always showed me that 
these questions had no interest for him, and that, in 
his opinion, the essential knowledge of the universe 
consisted in equations, formulae, and logarithmic series 
having for their object the mathematical theory of ve- 
locities and forces. 

But it is not the less surprising that he had not 
the curiosity to verify the position of his planet, which 
would have been easy, since it shows a planetary disk; 
and, besides, he might have had the aid of a chart, 
because he had only to ask for these charts from the 
Berlin Observatory, where they had just been finished 
and published. It is not the less surprising that Arago, 
who was more of a physicist than a mathematician, 
more of a naturalist than a calculator, and whose 
mind had so remarkable a synthetical character, had 
not himself directed one of the telescopes of the ob- 
servatory towards this point of the sky, and that no 
other French astronomer had this idea. But what sur- 
prises us still more is to know that nearly a year be- 



236 STORY OF TH£ SUN, MOON, AND STARS. 

fore, in October, 1845, a young student of the Uni- 
versity of Cambridge, Mr. Adams, had sought the 
solution of the same problem, obtained the same re- 
sults, and communicated these results to the director 
of the Greenwich Observatory, and that the astrono- 
mer to whom these results were confided had said 
nothing, and had not himself searched in the sky 
for the optical verification of his compatriot's solu- 
tion! 

This was indeed a triumph of human intellect. 
Yet it is no matter for human pride, but rather of 
thankfulness to God, who gave to man this marvelous 
reasoning power. And the very delight we have in 
such a success may humble us in the recollection of 
the vast amount lying beyond of the utterly unknown. 
But while the rare mind of a Newton could meekly 
realize the littleness of all he knew, lesser minds are 
very apt to be puffed up with the thought of what the 
human intellect can accomplish. 

Perhaps the chief feeling of lawful satisfaction in 
this particular discovery arises from the fact that it 
gives marked and strong proof of the truth of our 
present astronomical system and beliefs. Many mis- 
takes may be made, and much has often to be un- 
learned. Nevertheless, if the general principles of 
modern astronomy were wrong, if the commonly-re- 
ceived facts were a delusion, such complete success 
could not have attended so delicate and difficult a 
calculation. 

We do not know much about these two outer plan- 
ets, owing to their enormous distance from us. Uranus 
is in size equal to seventy-four earths, and Neptune is 



URANUS AND NEPTUNE. 237 

in size equal to one hundred and five earths. Both 
these planets are formed of somewhat heavier materials 
than Saturn, being about as dense as water. 

The size of the sun as seen from Uranus is about 
one three-hundred-and-ninetieth part of the size of 
the sun we see. To Neptune he shows a disk only 
one nine-hundredth part of the size of that visible to 
us — no disk at all, in fact, but only starlike brilliancy. 

The Uranian year lasts about eighty-four of our 
years; and this, with a very sloping axis, must cause 
most long and dreary winters, the tiny sun being hid- 
den from parts of the planet during half an earthly 
life-time. 

Uranus has at least four moons, traveling in very 
different planes from the plane of the ecliptic. Once 
it was thought that he had eight, but astronomers have 
since searched in vain for the other four, believed for 
a while to exist. Neptune has one moon, and may 
possess others not yet discovered. 

Sir Henry Holland, the celebrated physician, and 
a devoted student of astronomy, has left on record an 
incident of his life connected with the planet Neptune 
of singular interest. I give it here, and in his own 
words, because it is scarcely likely otherwise to fall 
under the notice of astronomical readers. After stating 
that his interest in astronomy had led him to take ad- 
vantage of all opportunities of visiting foreign observ- 
atories, he says : 

"Some of these opportunities, indeed, arising out 
of my visits to observatories both in Europe and 
America, have been remarkable enough to warrant a 
more particular mention of them. That which most 



238 STORY OF THF, SUN, MOON, AND STARS. 

strongly clings to my memory is an evening I passed 
with Encke and Galle in the observatory at Berlin, 
some ten or twelve days after the discovery of the 
planet Neptune on this very spot; and when every 
night's observations of its motions had still an espe- 
cial value in denoting the elements of its orbit. I 
had casually heard of the discovery at Bremen, and 
lost no time in hurrying on to Berlin. The night in 
question was one of floating clouds, gradually grow- 
ing into cumuli; and hour after hour passed away 
without sight of the planet which had just come to 
our knowledge by so wonderful a method of predic- 
tive research. Frustrated in this main point, it was 
some compensation to stay and converse with Encke 
in his own observatory, one signalized by so many 
discoveries, the stillness and darkness of the place 
broken only by the solemn ticking of the astronom- 
ical clock, which, as the unfailing interpreter of the 
celestial times and motions, has a sort of living exist- 
ence to the astronomer. Among other things discussed, 
while thus sitting together in a sort of tremulous 
impatience, was the name to be given to the new 
planet. Encke told me he had thought of * Vulcan/ 
but deemed it right to remit the choice to Leverrier, 
then supposed to be the sole indicator of the planet and 
its place in the heavens ; adding that he expected L,e- 
verrier's answer by the first post. Not an hour had 
elapsed before a knock at the door of the observatory 
announced the letter expected. Encke read it aloud; 
and, coming to the passage where Leverrier proposed 
the name of ( Neptune/ exclaimed, ' So lass den Na- 
men Neptun sein? 



URANUS AND NEPTUNE. 239 

It was a midnight scene not easily to be forgotten. 
A royal baptism, with its long array of titles, would 
ill compare with this simple naming of the remote 
and solitary planet thus wonderfully discovered. There 
is no place, indeed, where the grandeur and wild am- 
bitions of the world are so thoroughly rebuked and 
dwarfed into littleness as in the astronomical ob- 
servatory. As a practical illustration of this remark, 
I would add that my own knowledge of astronomers 
— those who have worked themselves with the tele- 
scope — has shown them to be generally men of tran- 
quil temperament, and less disturbed than others by 
worldly affairs, or by the quarrels incident even to 
scientific research." 

The same reasoning which has been used in refer- 
ence to Jupiter and his moons, and to Saturn and his 
moons, might perhaps be applied also to Uranus and 
Neptune and their moons. 

We know too little yet of their condition to venture 
far in such speculations. Still, taking the matter as 
a whole, there seem many reasons to incline us to the 
idea that each of the four greater outside planets may 
be a kind of secondary half-cooled sun to his satel- 
lites, helping to make up to them for the small amount 
of light and heat which they can obtain from the far- 
off sun. 



CHAPTER XX. 

COMETS AND METEORITES. 

A CURIOUS discovery has been lately made. It is 
that some sort of mysterious tie seems to exist be- 
tween comets and meteorites. For a long while this 
was never suspected. How should it be? The comets, 
so large, so airy, so light; the meteorites, so small, so 
solid, so heavy, — how could it possibly be supposed 
that the one had anything to do with the other? But 
supposings often have to give in to facts. Astrono- 
mers are gradually becoming convinced that there cer- 
tainly is a connection between the two. 

Strange to say, comets and meteorites occupy — 
sometimes, at least — the very same pathways in the 
heavens, the very same orbits round the sun. A cer- 
tain number of meteorite systems are now pretty well 
known to astronomers as regularly met by our earth 
at certain points in her yearly journey. Some of 
these systems or rings have each a comet belonging 
to it — not merely journeying near, but actually in its 
midst, on the same orbit. 

Perhaps it would be more correct to say that the 
meteorites belong to the comet, than that the comet 
belongs to the meteorites. We tread here on uncer- 
tain ground; for whether the meteorites spring from 
the comet, or whether the comet springs from the 
meteorites, or whether each has been brought into 

240 



COMETS AND METEORITES. 241 

existence independently of the other, no one can at 
present say. 

Though it is out of our power to explain the kind 
of connection, yet a connection there plainly is. So 
many instances are now known of a comet and a 
meteorite ring traveling together that it is doubtful 
whether any such ring could be found without a 
comet in its midst. By and by the doubt may spring 
up whether there ever exists a comet without a train 
of meteorites following him. 

Among the many different meteorite rings which 
are known, two of the most important are the so- 
called August and November systems. Of these two, 
the November system must claim our chief attention. 
Not that we are at all sure of these being the most 
important meteorite rings in the Solar System. On 
the contrary, as regards the November ring, we have 
some reason to think that matters may lie just the 
other way. 

The comet belonging to the November system is 
a small one — quite an insignificant little comet — only 
visible through a telescope. We do not, of course, 
know positively that larger comets and greater meteor- 
ite systems generally go together, but, to say the least, 
it seems likely. And if the greatness of a ring can 
at all be judged of by the size of its comet, then the 
November system must be a third-rate specimen of 
its kind. It is of particular importance to us, merely 
because it happens to be the one into which our 
earth plunges most deeply, and which we therefore 
see and know the best. The August ring is, on the 
contrary, connected with a magnificent comet, and 
16 



242 STORY OF THE SUN, MOON, AND STARS. 

may be a far grander system. But our pathway does 
not lead us into the midst of the August meteors as 
into those of November. We pass, seemingly, through 
its outskirts. 

The meteorites of the November system are very 
small. They are believed to weigh commonly only 
a few grains each. If they were larger and heavier, 
some of them would fall to earth as aerolites, not 
more than half-burnt in their rush through the atmos- 
phere. But this they are never found to do. 

There are known meteorite systems, which our 
earth merely touches or grazes in passing, from which 
drop aerolites of a very different description — large, 
heavy, solid masses. It is well for us that we do not 
plunge into the midst of any such ring, or we might 
find our air, after all, a poor protection. 

The last grand display of the November system of 
meteorites took place in the years 1866 to 1869, be- 
ing continued more or less during three or four No- 
vembers following. The next grand display will oc- 
cur in the year 1899. 

For this system — L,eonides, as it is called, because 
the falling-stars in this display seem all to shoot to- 
wards us from a spot in the constellation Leo — seems 
to have a "time" or "year" of thirty-three and a 
quarter earthly years. The shape of its orbit is a 
very long ellipse, near one end of which is the sun, 
while the other end is believed to reach farther away 
than the orbit of Uranus. 

A great deal of curiosity has been felt about the 
actual length and breadth and depth of the stream of 
meteorites through which our solid earth has so often 



COMETS AND METEORITES. 243 

plowed her way. During many hours at a time, 
lookers-on have watched the magnificent display of 
heavenly fireworks, — not a mere shooting-star here 
and there, as on common nights, but radiant meteors, 
flashing and dying by thousands through the sky. 
In 1866 no less than eight thousand meteors, in two 
hours and a quarter, were counted from the Green- 
wich Observatory in England. A natural wonder 
sprang up in many minds as to the extent of the ring 
from which they fell. 

For not in one night only, but in several nights 
during three or four years, and that not once only but 
once in every thirty-three years, thousands and tens 
of thousands appear to have been stolen by our earth 
from the meteorite-ring, never again to be restored. 
Yet each time we touch the ring, we find the abun- 
dance of little meteorites in nowise seemingly less- 
ened. 

When speaking of a "ring" of meteorites, it must 
not be supposed that necessarily the meteorites form 
a whole unbroken ring all round the long oval orbit. 
There may be no breaks. There may be a more or 
less thin scattering throughout the entire length of 
the pathway. But the meteorites certainly seem to 
cluster far more densely in some parts of the orbit 
than in other parts, and it was about the size of the 
densest cluster that so much curiosity was felt. 

Little can be positively known, though it is very 
certain that the cluster must be enormous in extent. 
Three or four years running, as our earth, after jour- 
neying the whole way round the sun, came again to 
that point in her orbit where she passes through the 



244 STORY OF THK SUN, MOON, AND STARS. 

orbit of the Leonides, she found the thick stream of 
meteorites still pouring on, though each year lessen- 
ing in amount. Taking into account this fact, and 
also the numbers that were seen to fall night after 
night, and also the speed of our earth, a "rough esti- 
mate " was formed. 

The length of this dense cluster is supposed to 
reach to many hundreds of millions of miles. The 
thickness or depth of the stream is calculated to be 
in parts over five hundred thousand miles, and the 
breadth about ten times as much as the depth. Each 
meteorite is probably at a considerable distance from 
his neighbor; but the whole mass of them, when in 
the near neighborhood of the sun, must form a mag- 
nificent sight. 

And if this be only a third-rate system, what must 
a first-rate system be like? And how many such sys- 
tems are there throughout the sun's wide domains? 
The most powerful telescope gives us no hint of the 
existence of these rings till we find ourselves in their 
midst. 

It may be that they are numbered by thousands, 
even by millions. The whole of the Solar System — 
nay, the very depths of space beyond — may, for aught 
we know, be crowded with meteorite systems. Every 
comet may have his stream of meteorites following 
him. But though the comet is visible to us, the me- 
teorites are not. Billions upon billions of them may 
be ever rushing round our sun, entirely beyond our 
ken, till one or another straggler touches our atmos- 
phere to flash and die as a " shooting star " in our sight. 

We have, and with our present powers we can 



COMETS AND METEORITES. 245 

have, no certainty as to all this. But I may quote 
here the illustration of a well-known astronomical 
writer on the subject. 

Suppose a blind man were walking out of doors 
along a high road, and during the course of a few 
miles were to feel rain falling constantly upon him. 
Would it be reasonable on his part, if he concluded 
that a small shower of rain had accompanied him along 
the road as he moved, but that fine weather certainly 
existed on either side of the road? On the contrary, 
he might be sure that the drops which he felt, were 
but a few among millions falling all together. 

Or, look at the raindrops on your window some 
dull day at home. Count how many there are? Could 
you, with any show of common sense, decide that 
those raindrops, and those alone, had fallen that day? 
So, when we find these showers of meteorites falling 
to earth, we may safely conclude that, for every one 
which touches our atmosphere, myriads rush elsewhere 
in space, never coming near us. 



CHAPTER XXI. 

MORE ABOUT COMETS AND METEORITES. 

Thk three prominent features of comets — a head, 
nucleus, and tail — are seen only in particular in- 
stances. The great majority appear as faint globular 
masses of vapor, with little or no central condensa- 
tion, and without tails. On the other hand, some 
have a strongly-defined nucleus, which shines with a 
light as vivacious as that of the planets, so as to be 
even visible in the daytime. This was the case with 
one seen at Rome soon after the assassination of Ju- 
lius Caesar, believed by the populace to be the soul of 
the dictator translated to the skies. The first comet 
of the year 1442 was also so brilliant, that the light of 
the sun at noon, at the end of March, did not prevent 
it from being seen ; and the second, which appeared 
in the summer, was visible for a considerable time 
before sunset. In 1532, the people of Milan were 
alarmed by the appearance of a star in the broad day- 
light ; and as Venus was not then in a position to be 
visible, the object is inferred to have been a comet. 
Tycho Brahe discovered the comet of 1577, from his 
observatory in the isle of Huene, in the sound, before 
sunset; and Chizeaux saw the comet of 1744, at one 
o'clock in the afternoon, without a telescope. 

The comet of 1843, already referred to in a previous 
chapter, was distinctly seen at noon by many persons 
in the streets of Bologna without the aid of glasses. 

246 



MORE ABOUT COMETS AND METEORITES. 247 

The nucleus is generally of small size, but the sur- 
rounding nebulosity, which forms the head, is often of 
immense extent; and the hazy envelope, the " horrid 
hair" of poetry, is sometimes seen separated from it 
by a dark space, encircling it like a ring. This was 
the aspect of the comet of 181 1. The entire diameter of 




THE GREAT COMET OF l8ll. 

the head measured 1,250,000 miles, and hence its bulk 
was nearly three times that of the sun, and four mil- 
lion times that of the earth. But such extraordinary 
dimensions are quite exceptional. 

Popular impressions respecting the supposed ter- 
restrial effects of the comet of 181 1 — a fine object in 
the autumn of that year, long remembered by many 
— are on record. It was gravely noted, that wasps 



248 STORY OF THE SUN, MOON, AND STARS. 

were very few in number ; that flies became blind, 
and disappeared early; and that twins were born more 
frequently than usual. The season was remarkable 
for its bountiful harvest an d abundant vintage. Grapes, 
figs, melons, and other fruits, were not only produced 
in extraordinary quantity, but of delicious flavor, so 
that " comet wines " had distinct bins allotted to them 
in the cellars of merchants, and were sold at high 
prices. There is, however, no fact better attested, by 
a comparison of observations, than that comets have 
no influence whatever in heightening or depressing 
the temperature of the seasons. The fine fruits and 
ample harvest of the year in question were, therefore, 
coincidences merely with the celestial phenomenon, 
without the slightest physical connection with it. 

Though the advanced civilization of recent times 
has led to juster views of cometary apparitions than 
to regard them as divinely-appointed omens of terres- 
trial calamity, yet society is apt to be nervous respect- 
ing these bodies, as likely to cause some great natural 
convulsion by collision with our globe. 

The great comet, which in 1683 received first the 
name of Halley's comet, appeared last in 1835, his 
return having been foretold within three days of its 
actually taking place. For Halley's comet is a mem- 
ber of the Solar System, having a yearly journey of 
seventy-six earthly years. He journeys nearer the 
sun than Venus, and travels farther away than 
Neptune. 

In the years 1858, 1861, and 1862, three more 
comets appeared, all visible without the help of a 
telescope. Of these three, Donati's comet, in 1858, 



MORE ABOUT COMETS AND METEORITES. 249 

was far superior to the rest. This fine object was 
first discovered on the 2d of June by Dr. Donati, at 
Florence. It appeared at first as a faint nebulous 
patch of light, without any remarkable condensation ; 
and as its motion towards the sun at that time was 
slow, it was not till the beginning of September that 




DONATI S COMET, 1858. 

it became visible to the naked eye. A short tail was 
then seen on the side opposite to the sun. 

The development was afterwards rapid, and the 
comet became equally interesting to the professional 
astronomer and to the unlearned gazer. In the first 
week of October the tail attained its greatest length, 
36 . At this time the tail was sensibly curved, and 



250 STORY OF THE SUN, MOON, AND STARS. 

had the appearance of a large ostrich-feather when 
waved gently in the hand. At the latter end of Octo- 
ber the comet was lost in the evening twilight. Its 
nearest approach to the earth was about equal to half 
the distance of the earth from the sun, and the nearest 
approach to Venus was about one-ninth part of that 
distance. An elliptical orbit, with a periodic time of 
more than 2,000 years, has been assigned to our late 
visitor. 

It was a singular fact about this comet that at one 
time the star Arcturus could be seen shining through 
the densest portion of the tail, close to the nucleus. 
Now, although the faintest cloud-wreath of earth 
would dim, if not hide, this star, yet the tail of the 
great comet was of so transparent a nature that Arc- 
turus shone undimmed, as if no veil had come be- 
tween. The exceedingly slight and airy texture of a 
comet's tail could hardly be more plainly shown. It 
was this gauzy appendage to a little nucleus which 
men once thought could destroy our solid earth at a 
single blow! 

These cometary trains generally appear straight, 
or at least, by the effect of perspective, they seem to 
be directed along the arcs of great circles of the celes- 
tial sphere. Some are recorded, however, which pre- 
sented a different appearance. Thus, in 1689, a comet 
was seen whose tail, according to the historians, was 
curved like a Turkish saber. This tail had a total 
length of 68°. It was the same with the beautiful 
comet of Donati, which we admired in 1858, and of 
which the tail had a very decided curvature. 

A comet can only be observed in the sky for a 



MORE ABOUT COMETS AND METEORITES. 25 1 

limited time. We perceive it at first in a region 
where nothing was visible on preceding days. The 
next day, the third day, we see it again; but it has 
changed its place considerably among the constella- 
tions. We can thus follow it in the sky for a certain 
number of days, often during several months; then we 
cease to perceive it. Often the comet is lost to view 
because it approaches the sun, and the vivid light of 
that body hides it completely; but soon we observe it 
again on the other side of the sun, and it is not till 
some time afterwards that it definitely disappears. 
Some have been visible at noonday, quite near the 
sun, like that of 1882, on September 17th. 

Yet, while taking care not to overrate, we must not 
underrate. True, the comets are delicate and slight 
in structure. One comet, in 1770, wandered into the 
very midst of Jupiter's moons, and so small was its 
weight that it had no power whatever, so far as has 
been detected, to disturb the said moons in their or- 
bits. Jupiter and his moons did very seriously dis- 
turb the comet, however; and when he came out 
from their midst, though none the worse for his ad- 
venture, he was forced to travel in an entirely new 
orbit, and never managed to get back to his old path- 
way again. 

But there are comets and comets, some being 
heavier than others. The comet named after Donati, 
albeit too transparent to hide a star, was yet so im- 
mense in size that his weight was calculated by one 
astronomer to amount to as much as a mass of water 
forty thousand miles square and one hundred and nine 
yards deep. 



252 STORY OF THK SUN, MOON, AND STARS. 

When first noticed, Donati's comet had, like all 
large comets, a bright envelope of light round the 
nucleus. After a while the one envelope grew into 
three envelopes, and a new tail formed beside the 
principal tail, which for a time was seen to bend 
gracefully into a curve, like a splendid plume. A 
third, but much fainter tail, also made its appearance, 
and many angry-looking jets were poured out from 
the nucleus. These changes took place while the 
comet was passing through the great heat of near 
neighborhood to the sun. Afterwards, as he passed 
away, he seemed gradually to cool down and grow 
quiet. The singular changes in the appearance of New- 
ton's comet have been earlier noticed. No marvel 
that he did undergo some alterations. The tremen- 
dous glare and burning heat which that comet had to 
endure in his rush past the sun, were more than 
twenty-five thousand times as much as the glare and 
heat of the fiercest tropical noonday ever known upon 
earth. Can we wonder that he should have shown 
"signs of great excitement, " that his head should have 
grown larger and his tail longer? 

It certainly was amazing, and past comprehension, 
that the said tail, over ninety millions of miles in 
length, should in four days have seemingly swept 
round in a tremendous half-circle, so as first to point 
in one direction, and then to point in just the opposite 
direction. 

We are much in the habit of speaking about 
comets as traveling through the heavens with their 
tails streaming behind them. But though this is 
sometimes the case, it is by no means always. 



more: about comets and meteorites. 253 

The tails of comets always stream away from the 
sun — whether before or behind the comet's head seem- 
ing to be a matter of indifference. As the comet comes 
hnrrying along his orbit, with ever-increasing speed, 
towards the snn, the head journeys first, and the long 
tail follows after. But as the comet rounds the loop 
of his orbit near the sun — the point nearest of all 
being called his perihelion — the head always remains 
towards the sun, while the tail swings, or seems to 
swing, in a magnificent sweep round, pointing always 
in the direction just away from the sun. 

Then, as the comet journeys with slackening speed, 
on the other side of his orbit, towards the distant 
aphelion, or farthest point from the sun, he still keeps 
his head towards the sun. So, at this part of his 
passage, in place of the head going first and the tail 
following after, the tail goes first and the head follows 
after. The comet thus appears to be moving back- 
wards; or, like an engine pushing instead of draw- 
ing a train, the head seems to be driving the tail 
before it. 

The sun, then, acts on these bodies when they ap- 
proach him, produces in them important physical and 
chemical transformations, and exercises on their de- 
veloped atmosphere a repulsive force, the nature of 
which is still unknown to us, but the effects of which 
coincide with the formation and development of the 
tails. The tails are thus, in the extension of the 
cometary atmosphere, driven back, either by the solar 
heat, by the light, by electricity, or by other forces; 
and this extension is rather a motion in the ether than 
a real transport of matter, at least in the great comets 



254 STORY. OF THE SUN, MOON, AND STARS. 

which approach very near the sun, and in their im- 
mense luminous appendages. The effects produced 
and observed"' are not the same in all comets, which 



GREAT COMET OF 1 744. 

proves that they differ from each other in several re- 
spects. The tails have sometimes been seen to di- 
minish before the perihelion passage, as in 1835, 



MORE ABOUT COMETS AND METEORITES. 255 

Luminous envelopes have also been seen succeeding 
each other round the head, concentrating themselves 
on the side opposite to the sun, and leaving the cen- 
tral line of the tail darker than the two sides. This 
is what happened in the Donati comet and in that of 
1861. Sometimes a secondary tail has been seen pro- 
jected towards the sun, as in 1824, 1850, 1851, and 
1880. Comets have been seen with the head envel- 




THE FIRST COMET OF 1888— JUNE 4. 

oped in phosphorescence, surrounding them with a 
sort of luminous atmosphere. Comets have also been 
seen with three, four, five, and six tails, like that of 
1744, for example, which appeared like a splendid 
aurora borealis rising majestically in the sky, until, 
the celestial fan being raised to its full height, it was 
perceived that the six jets of light all proceeded from 
the same point, which was nothing else but the nu- 
cleus of a comet. On the other hand, the nuclei 
themselves show great variations — some appear sim- 
ply nebulous, and permit the faintest stars to be vis- 



256 STORY OF TH£ SUN, MOON, AND STARS. 

ible through, them; others seem to be formed of one 
or more solid masses surrounded by an enormous at- 
mosphere; in others, again, a nucleus does not exist, 
as in the Southern comet of 1887. One of the comets 
of 1888 showed a triple nucleus and a bristling coma, 
as may be seen in the cut. We may, then, consider 
that the wandering bodies collected under the name 
of comets are of several origins and several different 
species. 

Why the tails of comets should so persistently 
avoid the sun it is impossible to say. We do not 
even know whether the cause lies actually in the sun 
or in the comet. Astronomers speak of the "repulsive 
energy" with which the sun "sweeps away" from his 
neighborhood the light vapory matter of which the 
tails are made. But the how and the wherefore of 
this strange seeming repulsion they can not explain. 
For at the selfsame time the sun appears to be attract- 
ing the comet towards himself, and driving the comet's 
tail away from himself. 

A few of the more well-known comets have been 
mentioned ; but a year rarely passes in which at least 
one comet is not discovered, though often only a small 
specimen, sometimes even tailless and hairless. No 
doubt many others pass unseen. The large and grand 
ones only come to view now and then. 

What are comets and meteorites made of? Re- 
specting comets, a good many ideas are put forth, and 
a good many guesses are made, as to "burning gas," 
"luminous vapor," "beams of light," and so on. But 
in truth, little is known about the matter. Respect- 
ing meteorites, we can speak more certainly. A good 



MORE ABOUT COMETS AND METEORITES. 257 

many meteorites have fallen to earth as aerolites, and 
have been carefully examined. They are found to 
contain nickel, cobalt, iron, phosphorus, and sometimes 
at least, a large supply of hydrogen gas. 

Not only do solid aerolites fall half-burnt to the 
ground, but even when the meteorites are quite con- 
sumed in the air, the fine dust remaining still sinks 
earthward. This fine dust has been found upon 
mountain-tops, and has been proved by close examina- 
tion to be precisely the same as the material of the 
solid aerolites. 

A luminous body of sensible dimensions rapidly 
traverses space, diffusing on all sides a vivid light — 
like a globe of fire of which the apparent size is often 
comparable with that of the moon. This body usually 
leaves behind it a perceptible luminous train. On or 
immediately after its appearance it often produces an 
explosion, and sometimes even several successive ex- 
plosions, which are heard at great distances. These 
explosions are also often accompanied by the division 
of the globe of fire into luminous fragments, more or 
less numerous, which seem to be projected in different 
directions. This phenomenon constitutes what is 
called a meteor, properly speaking, or a bolide. It is 
produced during the day as well as the night. The 
light which it causes in the former case is greatly en- 
feebled by the presence of the solar light, and it is 
only when it is developed with sufficient intensity that 
it can be perceived. 

In the British Museum there is a superb collection 
of meteorites. They have been brought together from 
all parts of the earth, and vary in size from bodies not 
17 



258 STORY OP THE sun, moon, and stars. 

much larger than a pin's-head up to vast masses 
weighing many hundred pounds. There are also 
many models of celebrated meteorites, of which the 
originals are dispersed through various other museums. 
Many of these objects have nothing very remark- 
able in their external appearance. If they were met 
with on the sea-beach, they would be passed by with- 
out more notice than would be given to any other 
stone. Yet what a history such a stone might tell us 
if we could only manage to obtain it! It fell; it was 
seen to fall from the sky ; but what was its course an- 
terior to that movement ? Where was it one hundred 
years ago, one thousand years ago? Through what 
regions of space has it wandered? Why did it never 
fall before? Why has it actually now fallen? Such 
are some of the questions which crowd upon us as we 
ponder over these most interesting bodies. Some of 
these objects are composed of very characteristic mate- 
rials. Take, for example, one of the more recent meteor- 
ites, known as the Rowton siderite. This body differs 
very much from the more ordinary kind of stony me- 
teorite. It is an object which even a casual passer- 
by would hardly pass without notice. Its great weight 
would also attract attention, while if it be scratched 
or rubbed with a file, it would be found that it was 
not in any sense a stone, but that it was a mass of 
nearly pure iron. We know the circumstances under 
which that piece of iron fell to the earth. It was on 
the 20th of April, 1876, about 3.40 P. M., that a strange 
rumbling noise, followed by a startling explosion, was 
heard over an area of several miles in extent among 
the villages in Shropshire. About an hour after this 



MORE ABOUT COMETS AND METEORITES. 259 

occurrence, a farmer noticed the ground in one of his 
grass-fields to have been disturbed, and he probed the 
hole which the meteorite had made, and found it, still 
warm, about eighteen inches below the surface. Some 
men working at no great distance had actually heard 
the noise of its descent, but without being able to in- 
dicate the exact locality. This remarkable object 
weighs 7^ pounds. It is an irregular angular mass 
of iron, though all its edges seem to have been rounded 
by fusion in its transit through the air, and it is cov- 
ered with a thick black film of the magnetic oxide of 
iron, except at the point where it first struck the 
ground. 

This siderite is specially interesting on account of 
its distinctly metallic character. Falls of the siderites, 
as they are called, are not so common as those of the 
stony meteorites ; in fact, there are only a few known 
instances of meteoric irons having been actually seen 
to fall, while the falls of stony meteorites are to be 
counted in scores or in hundreds. The inference is 
that the iron meteorites are much less frequent than 
the stony ones. 

It is a wonderful thought that we should really have 
these visitants from the sky, solid metal or showers of 
dust, coming to us from distant space. 

If the dust of thousands of meteorites is always 
thus falling earthward, one would imagine that it 
must in time add something to the weight of the 
earth. And this actually is the case. During the last 
three thousand years, no less than one million tons of 
meteorite-dust must, according to calculation, have 
fallen to earth out of the sky. A million tons is of 



26o STORY OF THE SUN, MOON, AND STARS. 



GREAT COMET OF l68o. 



course a mere nothing compared 
with the size of the world. Still, 
the fact is curious and interesting. 

It has been suggested thatper- 
haps the flames of the sun are 
partly fed by vast showers of fall- 
ing meteorites. It has even been 
suggested that perhaps, in long 
past ages, the earth and the plan- 
ets grew to their present size un- 
der a tremendous downpour of 
meteorites; the numbers which 
now drop to earth being merely 
the thin remains of what once 
existed. But for this guess there 
is no real foundation. 

Whether suns and worlds full- 
grown, created as in an instant; 
whether tiny meteorites in count- 
less myriads to be used as stones 
in "building;" whether vast 
masses of flaming gas, to be grad- 
ually cooled and "framed" into 
shape — which ever may have 
come first, and whichever may 
have been the order of God's 
working — still that "first" was 
made by him ; still he through- 
out was the Master-builder. 

A few words more about 
" comet- visitors." Many comets, 
as already stated, belong to our 



MORE ABOUT COMETS AND METEORITES. 261 



Solar System, though 
whether they have al- 
ways so belonged is an- 
other question. It is 
not impossible that they 
may once upon a time 
have wandered hence 
from a vast distance, 
and, being caught pris- 
oner by the powerful at- 
traction of Jupiter or 
one of his three great 
brother-planets, have 
been compelled thence- 
forth to travel in a closed 
pathway round the sun. 
There are also many 
comets which come once 
only to our system, flash- 
ing round past the sun, 
and rushing away in 
quite another direction, 
never to return. Where 
do these comets come 
from? And where do 
they go? From other 
suns — brother suns to 
ours? It may be. One 
is almost disposed to 
think that it must be so. 
Do we ever think 
what an immense voyage 




GREAT COMET OF 1 769. 



262 STORY OF THE SUN, MOON, AND STARS. 

they must have made to come from there to here? Do 
we imagine for how many years they must have flown 
through the dark immensity to plunge themselves into 
the fires of our sun? If we take into account the di- 
rections from which certain comets come to us, and if 
we assign to the stars situated in that region the least 
distances consistent with known facts, we find that 
these comets certainly left their last star more than 
twenty millions of years ago. 

In thus putting to us from the height of their ce- 
lestial apparitions so many notes of interrogation on 
the grandest problems of creation, comets assume to 
our eyes an interest incomparably greater than that 
with which superstition blindly surrounded them in 
past ages. When we reflect for a moment that a cer- 
tain comet which shines before us in the sky came 
originally from the depths of the heavens, that it has 
traveled during millions of years to arrive here, and 
that consequently it is by millions of years that we 
must reckon its age if we wish to form any idea of it, 
we can not refrain from respecting this strange visitor 
as a witness of vanished eras, as an echo of the past, 
as the most ancient testimony which we have of the 
existence of matter. But what do we say? These 
bodies are neither old nor young. There is nothing 
old, nothing new — all is present. The ages of the 
past contemplate the ages of the future, which all 
work, all gravitate, all circulate, in the eternal plan. 
Musing, you look at the river which flows so gently 
at your feet, and you believe you see again the river 
of your childhood; but the water of to-day is not that 
of yesterday, it is not the same substance which you 



MORE ABOUT COMETS AND METEORITES. 263 

have before your eyes, and never, never shall- this 
union of molecules, which you behold at this moment, 
come back there — never till the consummation of 
the ages! 

If the appearance of comets forebodes absolutely 
nothing as to the microscopical events of our ephem- 
eral human history, it is not the same with the effects 
which might be produced by their encounter with our 
wandering planet. In such an encounter there is 
nothing impossible. No law of celestial mechanics 
forbids that two bodies should come into collision in 
their course, be broken up, pulverized, and mutually 
reduced to vapor. 

I have before described some of the tremendous 
outbursts seen on the surface of our sun. It is be- 
lieved that in these outbursts matter is expelled, or 
driven forth, with such fearful violence as to send it 
whirling through space, never to fall back to the sun. 

Some meteorites may have their births thus. So 
also may some comets. And if all the stars are suns 
—huge fiery globes like our sun, and subject like him 
to tremendous eruptions — they too, probably, send out 
comets and meteorites to wander through space. 
Whether or no comets come into existence in any such 
manner, one thing seems pretty certain. Those com- 
ets which come to us from outside our system must 
come from some other system. And the nearest sys- 
tems known are those of the stars. 

The nearest star of all, whose distance has been 
measured, is Alpha Centauri. It has been roughly 
calculated that a comet, passing direct from Alpha 
Centauri to our sun, would take about twenty millions 



264 STORY OF THE SUN, MOON, AND STARS. 

of years for his journey. But here we tread upon 
very doubtful ground. Many matters, at present un- 
known to us, might greatly affect the result of such a 
calculation. Also it is by no means impossible that 




BARON ALEXANDER VON HUMBOLDT. 

other stars lie really much nearer to us than Alpha 
Centauri, whose distance astronomers have not yet 
attempted to measure. 

"In order to complete our view,'' says Alexander 



MORE ABOUT COMETS AND METEORITES. 265 

Von Humboldt, "of all that we have learned to con- 
sider as appertaining to our Solar System, which now, 
since the discovery of the small planets, of the inte- 
rior comets of short revolutions, and of the meteoric 
asteroids, is so rich and complicated in its form, it 
remains for us to speak of the ring of zodiacal light. 
Those who have lived for many years in the zone of 
palms must retain a pleasing impression of the mild 
radiance with which the zodiacal light, shooting 
pyramidally upward, illumines a part of the uniform 
length of tropical nights. I have seen it shine with 
an intensity of light equal to the Milky Way in Sag- 
gitarius, and that not only in the rare and dry atmos- 
phere of the summit of the Andes, at an elevation of 
from thirteen to fifteen thousand feet, but even on the 
boundless grassy plains of Venezuela, and on the sea- 
shore, beneath the ever-clear sky of Cumana. This 
phenomenon was often rendered especially beautiful 
by the passage of light, fleecy clouds, which stood out 
in picturesque and bold relief from the luminous back- 
ground. 

"This phenomenon, whose primordial antiquity 
can scarcely be doubted, is not the luminous solar at- 
mosphere itself, which can not be diffused beyond 
nine-tenths of the distance of Mercury. With much 
probability we may regard the existence of a very 
compressed ring of nebulous matter, revolving freely 
in space around the sun between the orbits of Venus 
and Mars, as the material cause ot the zodiacal light. 
These nebulous particles may either be self-luminous 
or receive their light from the sun. 

" I have occasionally been astonished, in the trop- 



266 STORY OF THK SUN, MOON, AND STARS. 

ical climates of South America, to observe the variable 
intensity of the zodiacal light. As I passed the nights, 
during many months, in the open air, on the shores of 
rivers and on plains, I enjoyed ample opportunities oi 
carefully examining this phenomenon. When the 
zodiacal light had been most intense, I have observed 
that it would be weakened for a few minutes, until it 
again suddenly shone forth in full brilliancy. In a 
few instances I have thought I could perceive, not 
exactly a reddish coloration, nor the lower portion 
darkened in an arc-like form, nor even a scintillation, 
but a kind of flickering and wavering of the light. 
Must we suppose that changes are actually in progress 
in the nebulous ring? Or is it not more probable that 
processes of condensation may be going on in the up- 
permost strata of the air, by means of which the trans- 
parency — or, rather, the reflection of light — may be 
modified in some peculiar and unknown manner? An 
assumption of the existence of such meteorological 
causes on the confines of our atmosphere is strength- 
ened by the sudden flash and pulsations of light which 
have been observed to vibrate for several seconds 
through the tail of a comet. During the continuation 
of these pulsations it has been noticed that the 
comers tail was lengthened by several degrees, and 
then again contracted." 



CHAPTER XXII. 

MANY SUNS. 

Once more we have to wing our flight far, far away 
from the busy Solar System where we live ; away from 
whirling planets, moons, meteorites, all shining with 
reflected sunlight; away from the great central sun 
himself, our own particular bright star. Once more 
we have, in imagination, to cross the vast, black, 
empty space — is it black, and is it empty, had we 
sight to see things as they are? — separating our sun 
from other suns, our star from other stars. For the 
sun is a star — only a star. And stars are suns — big, 
blazing suns. One is near, and the others are far 
away. That is the difference. 

We have no longer to do with bodies merely re- 
flecting another's light — always dark on one side and 
bright on the other — but with burning bodies, shining 
all round by their own light. We have no longer to 
picture just one single star with his surrounding 
worlds, but we have to fix our thoughts upon the 
great universe of stars or suns in countless millions. 

The earth is forgotten, with its small and ephem- 
eral history. The sun himself, with all his immense 
system, has sunk in the infinite night. On the wings 
of inter-sidereal comets we have taken our flight to- 
wards the stars, the suns of space. Have we exactly 
measured, have we worthily realized the road passed 
over by our thoughts ? The nearest star to us reigns 
at a distance of 275,000 times our distance from the 

267 



268 STORY OF THE SUN, MOON, AND STARS. 

sun ; out to that star an immense desert surrounds us, 
the most profound, the darkest, and the most silent 
of solitudes. 

The solar system seems to us very vast ; the abyss 
which separates our world from Mars, Jupiter, Saturn, 
and Neptune, appears to us immense ; relatively to 
the fixed stars, however, our whole system represents 
but an isolated family immediately surrounding us: 
a sphere as vast as the whole solar system would be 
reduced to the size of a simple point if it were trans- 
ported to the distance of the nearest star. The space 
which extends between the solar system and the stars, 
and which separates the stars from each other, appears 
to be entirely void of visible matter, with the excep- 
tion of nebulous fragments, cometary or meteoric, 
which circulate here and there in the immense voids. 
Nine thousand two hundred and fifty systems like 
ours, bounded by Neptune, would be contained in the 
space which isolates us from the nearest star! 

It is marvelous that we can perceive the stars at 
such a distance. What an admirable transparency 
in these immense spaces to permit the light to pass, 
without being wasted, to thousands of billions of 
miles! Around us, in the thick air which envelops 
us, the mountains are already darkened and difficult 
to see at seventy miles ; the least fog hides from us 
objects on the horizon. What must be the tenuity, 
the rarefaction, the extreme transparency of the ethe- 
real medium which fills the celestial spaces! 

The sun is center and ruler and king in his own 
system. But as a star, he is only one among many 
stars, some greater, some less than himself. From the 



MANY SUNS. 269 

far siderial heavens lie is hardly recognized even as a 
star among the constellations, so faint is his light. 

Do the snns which surround ns form a system 
with that which illuminates us, as the planets form 
one round our solar focus, and does our sun revolve 
round an attractive center? Does this center, the 
point of the revolutions of many suns, itself revolve 
round a preponderating center? In a word, is the 
visible universe organized in one or several systems? 
No Divine revelation comes to instruct men on the 
mysteries which interest them most — their personal or 
collective destinies. We have now, as ever, but science 
and observation to answer us. 

A problem so vast as this is still far from receiving 
even an approximate solution. From whatever point 
of view we consider it, we find ourselves face to face 
with the infinite in space and time. The present as- 
pect of the universe immediately brings into question 
its past and its future state, and then the whole of 
united human learning supplies us in this great re- 
search with but a pale light, scarcely illuminating the 
first steps of the dark and unknown road on which we 
are traveling. However, such a problem is worthy of 
engaging our attention, and positive science has al- 
ready made sufficient discoveries in the knowledge of 
the laws of nature to permit us to attempt to pene- 
trate these great mysteries. What is it that the gen- 
eral observation of the heavens — what is it that side- 
real synthesis teaches us on our real situation in 
infinitude ? 

In the calm and silent hours of beautiful evenings, 
what pensive gaze is not lost in the vague windings 



270 STORY OF THE SUN, MOON, AND STARS. 

of the Milky Way, in the soft and celestial gleam of 
that cloudy arch, which seems supported on two op- 
posite points of the horizon, and elevated more or less 
in the sky according to the place of the observer and 
the hour of the night? While one-half appears above 




A TELESCOPIC FIELD IN THE MILKY WAY. 

the horizon, the other sinks below it, and if we re- 
moved the earth, or if it were rendered transparent, 
we should see the complete Milky Way, under the 
form of a great circle, making the whole circuit of the 
sky. The scientific study of this trail of light, and 
its comparison with the starry population of the 



MANY SUNS. 271 

heavens, begins for us the solution of the great 
problem. 

Let us point a telescope towards any point of this 
stupendous arch. Suddenly hundreds, thousands of 
stars show themselves in the telescopic field, like 
needle-points on the celestial vault. Let us wait for 
some moments, that our eye may become accustomed 
to the darkness of the background, and the little 
sparks shine out by thousands. Let us leave the in- 
strument pointed motionless towards the same region, 
and there slowly passes before our dazzled vision the 
distant army of stars. In a quarter of an hour we 
see them appear by thousands and thousands. Will- 
iam Herschel counted three hundred and thirty-one 
thousand in a width of 5 in the constellation Cygnus, 
so nebulous to the naked eye. If we could see the 
whole of the Milky Way pass before us, we should see 
eighteen millions of stars. 

This seed-plot of stars is formed of objects indi- 
vidually invisible to the naked eye, below the sixth 
magnitude ; but so crowded that they appear to touch 
each other, and form a nebulous gleam which all hu- 
man eyes, directed to the sky for thousands of years, 
have contemplated and admired. Since it is devel- 
oped like a girdle round the whole circuit of the sky, 
we ourselves must be in the Milky Way. The first 
fact which impresses our mind is, that our sun is a star 
of the Milky Way. 

Thought travels fast — faster than a comet, faster . 
than light. A rushing comet would, it is believed, 
take twenty millions of years to cross the chasm be- 
tween the nearest known fixed star and us. Light, 



272 STORY OF THE SUN, MOON, AND STARS. 

flashing along at the rate of about one hundred and 
eighty-six thousand miles a second, will perform the 
same journey in four years and a third. But thought 
can overleap the boundary in less than a single 
moment. 

Each star that we see in the heavens is to our eye- 
sight simply one point of light. The brighter stars 
are said to be of greater magnitude, and the fainter 
stars of lesser magnitude ; yet, one and all, they have 
no apparent size. The most powerful telescope, though 
it can increase their brilliancy, can not add to their 
size. A planet, which to the naked eye may look like 
a star, will, under a telescope, show a disk, the breadth 
of which can be measured or divided; but no star has 
any real, visible disk in the most powerful telescope 
yet constructed. The reason of this is the enormous 
distance of the stars. Far off as many of the planets 
lie, yet the farthest of them is as a member of our 
household compared with the nearest star. 

I have already tried to make clear the fact of their 
vast distance. Light, which comes to us from the 
sun in eight minutes and a half, takes over four and a 
third years to reach us from Alpha Centauri. From 
this four-years-and-a-third length of journey between 
Alpha Centauri and earth, the numbers rise rapidly to 
twenty years, fifty years, seventy years, even hundreds 
of years. The distance of most of the stars is com- 
pletely beyond our power to measure. The whole 
orbit of our earth, nay, the whole wide orbit of the 
far-off Neptune, would dwindle down to one single 
point, if seen from the greater number of the stars. 

It used to be believed that, taking the stars gener- 



MANY SUNS. 273 

ally, there was probably no very marked difference 
in their size, their kind, their brightness. Some of 
course would be rather larger, and others rather 
smaller; still it was supposed that they might be 
roughly classed as formed much on the same scale 
and the same plan. But doubts are now felt about 
this notion. For a very similar idea used to be held 
with regard to the Solar System. The wonderful va- 
riety of form and richness in numbers, now known to 
abound within its limits, are discoveries of late years. 
May not the same variety in kind and size be found 
also among the stars? The more we look into the 
heavens, the more we find that dull, blank uniformity 
is not to be seen there. 

It is the same upon earth. Man builds his little 
rows of boxlike houses side by side, each one exactly 
like all the rest, or dresses his thousand soldiers in 
coats of the same cut and color, or repeats a neat leaf- 
design hundreds of times on carpets or wall-papers; 
but God never makes two leafs or two blades of grass 
alike. Wholesale turning out of things after one pat- 
tern is quite a human idea, not divine. 

We know so much about the stars as that some are 
at least considerably larger and some considerably 
smaller than others. When one star is seen to shine 
brightly, and another beside it shines dimly, we are 
apt to think that the brightest must be the near- 
est. Yet it is often impossible for us to say how much 
of the difference is owing to the greater distance of 
one or the other, to the greater size of one or the 
other, or to the greater brilliancy of one or the other. 
In many instances we do know enough to be quite 
18 



274 STORY OF THE SUN, MOON, AND STARS. 

sure that there is a great difference, not only in the 
distance of the stars, but in their size, their kind, their 
brightness. 

The stars have been lately classed by one or two 
astronomers into four distinct orders or degrees — 
partly depending on their color. The first class is 
that of the White Suns. These are said to be the 
grandest and mightiest of all. The star Sirius be- 
longs to the order of White Suns. Secondly comes 
the class of Golden Suns. To these blazing furnaces 
of yellow light, second only to the white-light stars, 
belongs our own sun. Thirdly, there are numbers of 
stars called Variable Stars, the light of which is con- 
stantly changing, now becoming more, now becoming 
less. Fourthly, there is the class of small Red Suns, 
about which not much is known. 

These four orders or divisions do not by any means 
include all the stars, or even all the single stars. 
Roughly speaking, however, the greater number of 
single stars, and many also of the double stars, belong 
to one or another of the above classes. 

When we talk of the different sizes of the different 
stars, it should be plainly understood that we have no 
means of directly measuring them. A point of light 
showing no disk, no surface, no breadth, can not be 
measured, for there is nothing to measure. 

In certain cases we are not entirely without the 
power of judging. The distances of a few of the 
stars from us have been found out. Knowing how 
far off any particular star is, astronomers are able to 
calculate exactly how bright our own sun would look 
at that same distance. If they find that our sun 



MANY SUNS. 275 

would shine just as the star in question shines, there 
is some reason for supposing that our sun and the 
star may be of the same size. If our sun would 
shine more brightly than the star shines, there is 
some reason for supposing that the star may be 
smaller than our sun. If our sun would shine more 
dimly than the star shines, there is some reason for 
supposing that the star may be larger than our sun, 

Other matters, however, have to be considered. 
Suppose we find a star at a certain distance shining 
twice as brilliantly as our own sun would shine at 
that same distance. Naturally, then, we say, That 
star must be much larger than our sun. 

The reasoning may be mistaken. We do not know 
the fact. What if, instead of being a much larger 
sun, it is only a much brighter sun? This possibly 
must be allowed for. It has, indeed, been strongly 
doubted by one astronomer, after close study of the 
sun, whether any surface of any star could exceed the 
surface of our sun in its power of light and heat. 

But Sirius sheds actually forty-eight times as much 
light around it as does our sun; we are not exactly 
entitled to say that Sirius is forty-eight times as big as 
the sun, but we can say that Sirius is forty-eight times as 
brilliant or as splendid. In making this calculation 
we have taken a lower determination of the bright- 
ness of Sirius relatively to the sun than some other 
careful observations would have warranted. It will 
thus be seen that if there be any uncertainty in 
our result it must only be as to whether Sirius is not 
really more than forty-eight times as bright as the 
sun. 



276 STORY OF TH3 SUN, MOON, AND STARS. 

When we picture to ourselves the star-depths, the 
boundless reaches of heavenly space, with these count- 
less blazing suns scattered broadcast throughout, we 
have not to picture an universe in repose. On the 
contrary, all is life, stir, energy. Just as in the busy 
whirl of our Solar System no such thing as rest is to 
be found, so also it seems to be in the wide universe. 

Every star is in motion. " Fixed," as we call 
them, they are not fixed. Invisible as their move- 
ments are to our eyes through immensity of distance, 
yet all are moving. Those silent, placid, twinkling 
specks of light are, in reality, huge, roaring, seeth- 
ing, tumultuous furnaces of fire and flame, heat and 
radiance. 

Bach, too, is hurrying along his appointed pathway 
in space. Some move faster, some move more slowly. 
One mile per second ; ten miles per second ; twenty, 
thirty, forty, fifty miles per second, — thus varying are 
their rates of speed. But whether fast or whether 
slowly, still onward and ever onward they press. 
Some are rushing towards us, some are rushing away 
from us. Some are speeding to the right, some are 
speeding to the left. 

The fine star Arcturus, which any one may admire 
every evening on the prolongation of the tail of the 
Great Bear, is slowly withdrawing from the fixed point 
where the celestial charts placed it two thousand years 
ago, and is moving towards the southwest. It takes 
eight hundred years to describe a space in the sky 
equal to the apparent diameter of the moon ; never- 
theless, this displacement was sufficiently perceptible 
to attract attention more than a century and a half 



MANY SUNS. 277 

ago, for Halley had noticed it in 17 18, as well as those 
of Sirins and Aldebaran. However slow it may ap- 
pear at the distance we are from Arcturus, this mo- 
tion is, at a minimum, 1,637 millions of miles a year. 
Sinus takes 1,338 years to pass over the same angular 
space in the sky ; at the distance of that star this is, 
at a minimum, 397 millions of miles per annum. The 
study of the proper motions of the stars has made the 
greatest progress in the last half-century, and espe- 
cially in recent years. All the stars visible to the 
naked eye and a large number of telescopic stars 
show displacements of this kind. 

Where are they going? Does any single star ever 
return to his starting-point — wherever that starting- 
point may have been? Do they journey in vast cir- 
cles or ellipses, round some far-distant center? What 
controls them all? Is it the mighty power of some 
such center, or does each star, by his faint and distant 
attraction, help to control all his brother-stars, to guide 
them on their appointed path, to preserve the delicate 
balance of a universe ? 

How little we know about the matter! Only so 
much we can tell— that the controlling and restrain- 
ing hand of God is over the whole. Whether by the 
attraction of one great center or by the united influ- 
ences of a thousand fainter attractions, he steers each 
radiant sun upon its heavenly path, " upholding all 
things by the words of his power." There is no 
blundering, no confusion, no entanglement. All is 
perfect order, calm arrangement, restrained energy. 



CHAPTER XXIII. 

SOME PARTICULAR SUNS. 

In the constellation of the Swan there is a little, 
dim, sixth-magnitude star, scarcely to be seen without 
a telescope. This star, 61 Cygni by name, is the first 
whose distance from us it was found possible to de- 
termine. 

We may think it strange that so faint a star was 
even attempted. Would not astronomers have nat- 
urally supposed it to be one of the farther-distant 
stars? No, they did not. For though 61 Cygni 
showed but a dim light, yet his motion — not the daily 
apparent motion, but the real motion as seen from 
earth — was found to be so much more rapid than the 
motion of most other stars that they rightly guessed 
61 Cygni to be a rather near neighbor of ours. 

Do not misunderstand me, when I speak of " more 
rapid motion, " and of " rather near neighborhood.' * 
The real rate of 61 Cygni's rush through space is be- 
lieved to be about forty miles each second, or one 
thousand four hundred and fifty millions of miles 
each year. All we can perceive of this quick mo- 
tion is that, in the course of three hundred and 
fifty years, 61 Cygni travels over a space in the sky 
about as long as the breadth of the full moon. Little 
enough, yet very far beyond what can be detected in 
the greater number of even the brightest stars. 

Then, again, as to the near neighborhood of this 

278 



SOMB PARTICULAR SUNS. 



279 



•6I6ygni #DENEB 



star, 61 Cygni is near enough to have his distance 
measured, and that is saying a good deal. Alpha 
Centauri, the nearest star of which we know in the 
southern heavens, is two hundred and seventy-five 
thousand times as far distant as the sun. But 6 1 Cygni, 
the nearest star of which we know in the northern 
heavens, is nearly twice as far away as Alpha Centauri. 

We call 61 Cygni a star, for so he appears to com- 
mon observers. In reality, instead of being only one 
star, the speck of 
light which we call 
61 Cygni consists 
of two stars. The ***'" 
two are separated 
by a gap about half 
as wide again as 
the wide gap be- 
tween the sun and 
Neptune. Yet so 
great is their dis- 
tance from us that to the naked eye the two seem to be 
one. These two suns would together make a sun only 
about one-third as large as our sun. They differ in 
size, the quicker movements of one showing it to be 
the smaller; and it is by means of their known dis- 
tance from one another, and their known rate of mo- 
tion, that their size, or rather their weight, can be 
roughly calculated. Of course neither of the two 
shows any actual measurable disk. So much and so 
little is with tolerable certainty known about this 
particular pair of suns. 

Next let us turn to Alpha Centauri — named Alpha, 



^ 



A* 



& 



CYGNUS. 



28o STORY OF THE SUN, MOON, AND STARS. 

the first letter of the Greek alphabet, because it is 
the brightest star in the constellation of the Centaur. 
The second brightest star in a constellation is gener- 
ally called Beta, the third Gamma, the fourth Delta, 
and so on; just as if we were to name them A, B, 
C, D, in order of brightness. 

The constellation Centaur lies in the southern 
heavens, close to the beautiful constellation called the 
Southern Cross, and is invisible in the northern hem- 
isphere. Of all the stars shining in the heavens 
round our earth, two only — Sirius and Canopus — show 
greater brilliancy than Alpha Centauri. 

As in the case of 61 Cygni, astronomers were led to 
attempt the measurement of Alpha Centauri's dis- 
tance, by noticing how much more distinct were his 
movements than the movements of other stars, though 
less rapid both to the eye and in reality than those of 
61 Cygni. Alpha Centauri's rate of motion is some 
thirteen miles each second. 

And this, so far as we yet know, is our sun's near- 
est neighbor in the heavens outside his own family 
circle. 

Strange to say, Alpha Centauri, like 61 Cygni, con- 
sists, not of a single star, but of a pair of stars. It is 
a two-sun system — whether or no surrounded by plan- 
ets can not be told. We can only reason from what 
we see to what we do not see. And as God did not 
form our earth "in vain," and did not form our sun 
"in vain," so we firmly believe that he did not form 
"in vain" any one of his myriads of suns scattered 
through space. What is, has been, or will be the 
particular use of each one, it would be rash to at- 



SOME PARTICULAR SUNS. 



28l 



tempt to say. But that many among them have, like 
our own sun, systems of worlds revolving round them, 
we may safely consider very probable. 

The two suns of the Alpha Centauri double-star 




STARS WHOSE DISTANCES ARE BEST KNOWN. (See Table.) 

are separated by a distance about twenty-two times as 
great as the distance of the earth from the sun, yet to 
the naked eye they show as a single star. Here again 
one is much smaller than the other ; and the smaller 
revolves round the larger in about eighty-five years. 
It is believed that the two together would form a 



282 STORY OF THE SUN, MOON, AND STARS. 



sun about twice as large and heavy as our sun. This 
belief is strengthened by the great brilliancy of Alpha 
Centauri. Our own sun, placed at that distance from 
us, would shine only one-third as brightly as he does 

STARS WHOSE DISTANCES ARE BEST KNOWN. 



I 
2 

3 
4 
5 
6 

7 
8 

9 
io 
II 

12 

13 
14 

15 
16 

17 

iS 
19 

20 
21 
22 
23 



NAME OF STAR. 



Alpha Centauri, 
6i Cygni, . . . 
2,398, Draco, . 
Sirius, .... 
9,352, Lacaille, 
Procyon, . . . 
Lalande, 21,258, 
O^Ltzen, 11,677, 
Sigma Draconis 
Aldebaran, . . 
Epsilon Indi, . 
CEltzen, 17,415 
1,516, Draco, . 
Omicrou Eridani, 
Altair, .... 
Bradley, 3,077, 
Eta Cassiopeise 

Vega, 

Capella, .... 
Arcturus, . . . 
Pole Star, . . 
Mu Cassiopeise, 
1,830, Groombridge 



MAG- 
NITUDE. 



1.0 

5-i 
8.2 
1.0 
7-5 
i-3 
8-5 
9.0 

4-7 
1-5 
5-2 
9.0 
7.0 
4.4 
1.6 
5-5 
3-6 
1.0 
1.2 
1.0 
2.1 
5-2 

6.5 



DISTANCE IN 
MILES. 



25 trillions. 

43 " 

55 " 

58 " 

66 

71 " 

74 " 

74 " 

78 

81 

87 

94 " 
101 
101 
101 

IOI " 

118 
128 

174 

204 " 

215 
320 

426 



This table presents the most trustworthy data which 
we have yet obtained with reference to stellar dis- 
tances. As a great number of attempts have been 
made on stars which, by their brightness or by the 
magnitude of their proper motion, would appear to be 
the nearest to us, we may believe that the star now 
considered as the nearest is really so, and that there 
is no other less distant. Thus our sun, a star in the 
immensity, is isolated in infinitude, and the nearest 



SOMB PARTICULAR SUNS. 283 

sun reigns at twenty-five trillions of miles from our 
terrestrial abode. Notwithstanding its unimaginable 
velocity of 186,400 miles a second, light moves, flies, 
during four years and one hundred and twenty-eight 
days to come from this sun to us. Sound would take 
more than three millions of years to cross the same 
abyss. At the constant velocity of thirty-seven miles 
an hour, an express train starting from the sun Alpha 
Centanri would not arrive here till after an uninter- 
rupted course of nearly seventy-five millions of years. 

Here, then, are the nearest suns to us. These stars, 
twenty-three in number, are almost the only ones 
which have shown a perceptible parallax ; still the re- 
sult is very doubtful for the last four, of which the 
parallax is less than a tenth of a second. Attempts 
have been made to ascertain the parallax of all the 
stars of the first magnitude, and the result has been 
negative for those which are not entered in this 
list. Canopus, Rigel, Betelgeuse, Achernar, Alpha of 
the Cross, Antares, Spica, and Fomalhaut, do not show 
a perceptible parallax. The fine star Alpha Cygni, 
which shines near 61 Cygni, does not present to the 
most accurate researches any trace of fluctuation : it is, 
then, incomparably more distant than its modest neigh- 
bor — at least five times, and perhaps twenty times, 
fifty times, one hundred times beyond that. What must 
be the colossal size and amazing light of these suns, 
of which the distance is greater than three hundred 
to four hundred trillions of miles, and which never- 
theless still shine with so splendid a brightness ! 

We did not know the distance of any stars till the 
year 1840. This shows how recent this discovery is ; 



284 STORY OF THE SUN, MOON, AND STARS. 

indeed, we have hardly now begun to form an approxi- 
mate idea of the real distances which separate the 
stars from each other. The parallax of 61 Cygni, the 
first which was known, was determined by Bessel, 
and resulted from observations made at Konigsberg 
from 1837 to 1840. Since then, the first figure ob- 
tained has been corrected by a series of more recent 
observations. 

Such distances are amazing and almost terrifying 
to the imagination. The mind is bewildered and al- 
most overwhelmed when attempting to form a concep- 
tion of such portions of immensity, and feels its own 
littleness, the limited nature of its powers, and its ut- 
ter incapacity for grasping the amplitudes of creation. 
But though it were possible for us to wing our flight 
to such a distant orb as 61 Cygni, we should still find 
ourselves standing only on the verge of the starry fir- 
mament where ten thousands of other orbs a thou- 
sand times more distant would meet our view. We 
have reason to believe that a space equal to that 
which we are now considering intervenes between 
most of the stars which diversify our nocturnal sky. 
The stars appear of different magnitudes; but we 
have the strongest reason to conclude that in the ma- 
jority of instances this is owing, not to the difference 
of their real magnitudes, but to the different distances at 
which they are placed from our globe. 

If, then, the distance of a star of the first or second 
magnitude, or those which are nearest to us, be so im- 
mensely great, what must be the distance of stars of 
the sixteenth or twentieth magnitude, which can be 
distinguished only by the most powerful telescopes? 



SOME PARTICULAR SUNS. 285 

Some of these must be many millions of times more 
distant than the nearest star whose distance now ap- 
pears to be determined. And what shall we think of 
the distance of those which lie beyond the reach of 
any telescope that has yet been constructed, stretch- 
ing beyond the utmost limits of mortal vision, within 
the unexplored regions of immensity? Here even 
the most vigorous imagination drops its wing, and 
owns itself utterly unable to penetrate this mysterious 
and boundless unknown. 

Turning now from the sun, whose distance was 
first measured, and from the nearest star with which 
we are acquainted, let us think about the most radiant 
star in the heavens — Sirius, " the blazing Dog-star of 
the ancients;" named by one astronomer "the king of 
suns." 

First, as to the color of Sirius. He belongs to the 
order of "White Suns," and among all the white suns 
known to us, Sirius ranks as chief. There may be 
many at greater distances far surpassing him in size, 
and weight, and brilliancy; but we can only speak so 
far as we know. Strange to say, Sirius was not always 
a "white sun;" for ancient writers describe him as 
being, in their days, a red star. This change is very 
singular, and difficult to understand. But Sirius is 
not the only example of the kind. Many alterations 
in color have been noticed as taking place, often in a 
much shorter space of time. For instance, one star, 
which was a white sun in the days of Herschel, is now 
a golden sun. 

Secondly, as to the distance of Sirius. Like a few 
other stars, Sirius lies not quite so far away as to be 



286 STORY OF THE SUN, MOON, AND STARS. 

beyond reach of measurement. No base-line upon 
earth would cause the slightest seeming change of 
position in him ; but as our earth journeys round the 
sun, the line from one side of her orbit to the other is 
found wide enough. A base-line of one hundred and 
eighty-six millions of miles does cause just a tiny 
seeming change. 

It is very little even with Alpha Centauri, and with 
Sirius it is much less. The " displacement " of Sirius 
is so slight that to measure his distance with exact- 
ness is impossible. Sirius lies more than twice as 
far away from earth as Alpha Centauri. To reach 
Sirius, the straight line between earth and sun must 
be repeated six hundred and twenty-six thousand 
times. Light, which reaches us from the sun in eight 
minutes and a half, and from Alpha Centauri in four 
years and a third, can not reach us from Sirius in 
less than nine years. 

Thirdly, as to the size of Sirius. Here, of course, 
we are in difficulties. Radiantly as Sirius shines on a 
clear night, and dazzling as he looks through a power- 
ful telescope, he shows no real disk or round surface, 
but only appears as one point of brilliant light. Some 
believe him to be much the same size as our sun, while 
others believe him to be very much larger. But we 
have no certain ground to rest upon. The only safe 
method of calculating the probable size — or, rather, 
weight — of a star is through the discovery of a com- 
panion, and a knowledge of its distance from the chief 
star, and its time of revolution round the chief star. 

Fourthly, as to the motions of Sirius — not his 
nightly apparent movement, caused by the earths 



SOME PARTICULAR SUNS. 287 

turning on her axis, but his real journey through 
space. For a long while it was only possible to ob- 
serve the movements of a star when the star was trav- 
eling sideways to us across the sky. A star coming 
straight towards us, or going straight away from us, 
would seem to be at rest. Lately, however, by means 
of that remarkable instrument, the spectroscope, it 
has been found possible to measure the motions of 
stars coming towards or going away from us. This 
is possible as yet only in a few scattered cases, but 
among those few is the brilliant Sirius. 

The sideways motion of Sirius had been known 
before. It now appears that he does not move exactly 
sideways to us, but is rushing away in a slanting di- 
rection at the rate of thirty miles each second, or about 
one thousand millions of miles a year. 

How many millions upon millions of miles Sirius 
must now be farther from us than in the days of the 
ancients ! Yet he shines still, the most brilliant star 
in the sky. So small a matter are all those millions 
of miles, compared with the whole of his vast dis- 
tance from us, that we do not perceive any lessening 
of light. 

It is an interesting fact that while Sirius is moving 
away from us, we are also moving away from him. 
Our "first station ahead," in the constellation Her- 
cules, lies exactly in the opposite direction from Sirius. 
But the sun does not move so fast as Sirius. He is 
believed to accomplish only about one hundred and 
fifty millions of miles each year, drawing all his planets 
with him. 

Fifthly, has Sirius a family, or system, like that of 



288 STORY OF THE SUN, MOON, AND STARS. 

our sun? Why not? Common sense and reason alike 
answer with a <( Probably, yes" — not only about Sirius, 
but about other stars also. No doubt the systems — 
the number, size, weight, speed, distance, and kind of 
planets — differ very greatly. No doubt there are 
boundless varieties of beauty and grandeur. 

But that our sun should be the head of so wonder- 
ful and complex a system, that his rays should be the 
source of life and heat to so many dependents, and 
that all the myriads of suns besides should be mere 
solitary lamps shining into empty space, warming, 
lighting, controlling nothing, is an idea scarcely to be 
looked in the face. 

Of course, there may be other and different uses 
for some of these suns, beyond our understanding. 
We must not be positive in the matter. It seems, 
however, pretty certain that Sirius at least is not a 
solitary, unattended sun. 

Astronomers, carefully watching his movements, 
were somewhat perplexed. As with Uranus, the at- 
traction of a heavy body beyond was suspected from 
the nature of the planet's motions, so it happened 
again with the far more distant Sirius. Astronomers 
could only explain his movements by supposing the 
attraction of some large and near satellite. No one 
knew anything about such a satellite, but it was felt 
that one must exist. 

Nearly twenty years had elapsed after Bessel had 
predicted the disturber of Sirius before the telescopic 
discovery which confirmed it was made. The circum- 
stances under which that discovery was made are not, 
indeed, so dramatic as those which attended the dis- 



SOME PARTICULAR SUNS. 289 

covery of Neptune, but yet they have an interest of 
their own. In February, 1862, Alvan Clark & Sons, 
the celebrated telescope-makers, of Cambridge, Massa- 
chusetts, were completing a superb eighteen-inch ob- 
ject-glass for the Chicago Observatory. Turning the 
instrument on Sirius, for the purpose of trying it, the 
practiced eye of Alvan Graham Clark, the son, soon 
detected something unusual, and he exclaimed, "Why, 
father, the star has a companion !" The father looked, 
and there was a faint companion due east from the 
bright star, and distant about ten seconds of a degree. 
This was exactly the predicted direction of the com- 
panion of Sirius, and yet the observers knew nothing 
of the prediction. As the news of this discovery 
spread, many great telescopes were pointed on Sirius ; 
and it was found that when observers knew exactly 
where to look for the object, many instruments would 
show it. The new companion star to Sirius lay in the 
true direction, and it was now watched with the keen- 
est interest, to see whether it also was moving in the 
way it should move, — if it were really the body whose 
existence had been foretold. Four years of observa- 
tion showed that this was the case, so that hardly any 
doubt could remain that the telescopic discovery had 
been made of the star which had caused the inequality 
in the motion of Sirius. 

It is certainly a very remarkable fact that, out of 
the thousands of stars with which the heavens are 
adorned, no single star has yet been found which cer- 
tainly shows an appreciable disk in the telescope. We 
are aware that some skillful observers have thought 
that certain small stars do show disks ; but we may 
19 



290 STORY OF THE SUN, MOON, AND STARS. 

lay this aside, and appeal only to the ordinary fact 
that onr best telescopes turned on the brightest stars 
show merely glittering points of light, so hopelessly 
small as to elude our most delicate micrometers. The 
ideal astronomical telescope is, indeed, one which will 
show Sirius, or any other bright star, as nearly iden- 
tical as possible with Euclid's definition of a point, 
being that which has no parts and no magnitude. 

Lastly, what is Sirius made of? The late discovery 
of spectrum analysis, or of the instrument called the 
spectroscope, helps us here. A little further explana- 
tion on this subject will be given later. It may be 
observed in passing that before the said discovery, 
astronomers can scarcely be asserted to have known 
with any certainty that stars were suns. They could, 
indeed, be sure that at the vast distances of the fixed 
stars no bodies, shining by merely reflected light, 
could possibly be visible to us. But there knowledge 
stopped. 

Now we can say more. Now the spectroscope, by 
breaking up and dividing for us the slender ray of 
light traveling from each star, has shown to us some- 
thing of the nature of the stars. Now we know that 
the stars, like our sun, are burning bodies, surrounded 
by atmospheres full of burning gas. 

It has even been found out that in Sirius there are 
large quantities of sodium and magnesium, besides 
other metals, and an abundant supply of hydrogen gas. 



CHAPTER XXIV. 

DIFFERENT KINDS OF SUNS. 

Various in kind, various in size, various in color, 
various in position, various in motion, are trie myriad 
suns scattered through space. So far are they from 
being formed on the same plan, turned out on the 
same model, that it may with reason be doubted 
whether any two stars could be found exactly alike. 
Why should we expect to find them so? No two oak- 
leaves, no two elm-leaves, precisely alike, are to be 
found upon earth. 

So some stars are large, some are small. Some are 
rapid in movement, some are slow. Some are yellow, 
some white, some red, green, blue, purple, or gray. 
Some are single stars; others are arranged in pairs, 
trios, quartets, or groups. Some appear only for a 
time, and then disappear altogether. Others are 
changeful, with a light that regularly waxes and 
wanes in brightness. 

We have now to give a little time and thought to 
variable stars and temporary stars; afterwards to 
double stars and colored stars. There are many stars 
which pass through gradual and steady changes — first 
brightening, then lessening in light, then brightening 
again. One such star is to be seen in the constella- 
tion of the Whale. It is named "Mira," or "The 
Marvelous," and the time in which its changes take 
place extends to eleven months. For about one fort- 

291 



292 STORY OF THE SUN, MOON, AND STARSo 

night it is a star of the second magnitude. Through 
three months it grows slowly more and more dim, till 
it becomes invisible, not only to the naked eye, but 
through ordinary telescopes. About five months it 
remains thus. Then again, during three months, it 
grows brighter and brighter, till it is once more a 
second-magnitude star, and after a fortnight's pause 
begins anew to fade. 

At its maximum, this star is yellow; when it is 
faint, it is reddish. Spectrum analysis shows in it a 
striped spectrum of the third type, and when its light 
diminishes it preserves all the principal bright rays 
reduced to very fine threads. The most plausible ex- 
planation of this variability is to suppose that it peri- 
odically emits vapors similar to the eruptions ob- 
served in the solar photosphere. Instead of its 
periodicity being like that of the sun — eleven years 
and hardly perceptible — this variation of the sun of 
the Whale is three hundred and thirty-one days and 
very considerable. It is subject to oscillations and ir- 
regularities similar to those which we remark in our 
sun. Of all the variable stars, this is the easiest to 
observe, and it has been known for nearly three hun- 
dred years. 

The most celebrated of all the variable stars is 
that known as Algol, in the constellation of Perseus. 
This star is very conveniently placed for observation, 
being visible every night in the Northern Hemisphere, 
and its wondrous and regular changes can be observed 
without any telescopic aid. Every one who desires to 
become acquainted with the great truths of astronomy 
should be able to recognize this star, and should have 



DIFFERENT KINDS OF SUNS. 293 

also followed it during one of its periods of change. 
Algol is usually a star of the second magnitude; but 
in a period between two or three days — or, more ac- 
curately, in an interval of two days, twenty hours, 
forty-eight minutes, and fifty-five seconds — its brill- 
iancy goes through a most remarkable cycle of varia- 
tions. The series commences with a gradual decline 
of the star's brightness, which, in the course of three 
or four hours, falls from the second magnitude down 
to the fourth. At this lowest stage of brightness, Al- 
gol remains for about twenty minutes, and then begins 
to increase, until in three or four hours it regains the 
second magnitude, at which it continues for about two 
days, thirteen hours, when the same series commences 
anew. It seems that the period required by Algol to 
go through its changes is itself subject to a slow, but 
certain variation. 

Another variable star, Betelgeuse in Orion, under- 
goes its variations in about two hundred days ; while 
yet another, Delta Cephei, takes only six days. Our 
own sun is believed to be in some slight degree a 
variable star, passing through his changes in eleven 
years. When the sun-spots are most numerous, he 
would probably appear, if seen from a great distance, 
more dim than when there are few or none of them. 

Sometimes a star is not merely variable. Stars have 
appeared for a brief space, and then utterly vanished. 
They are then named Temporary Stars. Whether 
such a star really does go out of existence, or whether 
it merely becomes too dim to be seen ; whether the 
furnace-fires are extinguished, and the glowing sun 
changes into a dark body, or whether it merely turns 



294 STORY OF THE SUN, MOON, AND STARS. 

a dark side towards us for a very long period, — these 
are questions we can not answer. 

An extraodinary specimen of a temporary star was 
seen in 1572. It was not a comet, for it had no coma 
or tail, and it never moved from its place. The bright- 
ness of the star was so great as to surpass Sirius and 
Jupiter, and to equal Venus at her greatest brilliancy. 
Nay, it must have surpassed even Venus, for it was 
plainly visible at midday in a clear sky. Gradually 
the light faded and grew more dim, till at length it 
entirely disappeared. As it lessened in brilliancy, it 
also changed in color, passing from white to yellow, 
and from yellow to red. This curiously agrees with 
the three tints of the first, second, and fourth orders 
of suns, as lately classified. 

This star was observed by Tycho Brahe, who gives 
the following curious account : 

" One evening, when I was contemplating, as usual, 
the celestial vault, whose aspect was so familiar to me, 
I saw, with inexpressible astonishment, near the zenith, 
in Cassiopeia, a radiant star of extraordinary magni- 
tude. Struck with surprise, I could hardly believe my 
eyes. To convince myself that it was not an illusion, 
and to obtain the testimony of other persons, I called 
out the workmen employed in my laboratory, and 
asked them, as well as all passers-by, if they could 
see, as I did, the star, which had appeared all at once. 
I learned later on that in Germany carriers and other 
people had anticipated the astronomers in regard to a 
great apparition in the sky, which gave occasion to 
renew the usual railleries against men of science (as 
with comets whose coming had not been predicted). 



DIFFERENT KINDS OF SUNS. 295 

" The new star was destitute of a tail ; no nebulos- 
ity surrounded it ; it resembled in every way other stars 
of the first magnitude. Its brightness exceeded that 
of Sirius, of Lyra, and of Jupiter. It could only be 
compared with that of Venus when it is at its nearest 
possible to the earth. Persons gifted with good sight 
could distinguish this star in daylight, even at noon- 
day, when the sky was clear. At night, with a cloudy 
sky, when other stars were veiled, the new star often 
remained visible through tolerably thick clouds. The 
distance of this star from the other stars of Cassio- 
peia, which I measured the following year with the 
greatest care, has convinced me of its complete im- 
mobility. From the month of December, 1572, its 
brightness began to diminish; it was then equal to 
Jupiter. In January, 1573, it became less brilliant 
than Jupiter; in February and March, equal to stars 
of the first order ; in April and May, of the brightness 
of stars of the second order. The passage from the 
fifth to the sixth magnitude took place between De- 
cember, 1573, and February, 1574. The following 
month the new star disappeared without leaving a 
trace visible to the naked eye, having shone for seven- 
teen months." 

These circumstantial details permit us to imagine 
the influence which such a phenomenon must have ex- 
ercised on the minds of men. Few historical events 
have caused so much excitement as this mysterious 
envoy of the sky. It first appeared on November 11, 
1572. General uneasiness, popular superstition, the 
fear of comets, the dread of the end of the world, long 
since announced by the astrologers, were an excellent 



296 STORY OK THB SUN, MOON, AND STARS. 

setting for such an apparition. It was soon announced 
that the new star was the same which had led the wise 
men to Bethlehem, and that its arrival foretold the re- 
turn of the Messiah and the last judgment. For the 
hundredth time, perhaps, this sort of prognostication 
was recognized as absurd. It did not, however, pre- 
vent the astrologers from being believed, twelve years 
later, when they announced anew the end of the 
world for the year 1588 ; these predictions exercised 
the same influence on the public mind. 

After the star of 1572 the most celebrated is that 
which appeared in October, 1604, in Serpentarius, and 
which was observed by two illustrious astronomers, 
Kepler and Galileo. As happened with the preceding, 
its light imperceptibly faded. It remained visible for 
fifteen months, and disappeared without leaving any 
traces. In 1670 another temporary star, blazing out 
in the head of the Fox (Vulpecula), showed the singu- 
lar phenomenon of being extinguished and reviving 
several times before it completely vanished. We know 
of twenty-four stars which, during tlie last two thou- 
sand years, have presented a sudden increase of light; 
have been visible to the naked eye, often brilliant; and 
have then again become invisible. The last appari- 
tions of this kind happened before our eyes in 1866, 
1876, 1885, and 1892, and spectrum analysis enabled 
us to ascertain, as we have seen, that they were due to 
veritable combustion — a fire caused by a tremendous 
expansion of incandescent hydrogen, and to phenom- 
ena analogous to those which take place in the solar 
photosphere. A rather curious fact about these stars 
is, that they do not blaze out indifferently in any point 



DIFFERENT KINDS OF SUNS. 297 

of the sky, but in rather restricted regions, chiefly in 
the neighborhood of the Milky Way. 

Many other instances have been known, beside 
those referred to, of variable and temporary stars. 

There are two distinct kinds of double-stars. First, 
we have those which merely seem to be double, be- 
cause one lies almost directly behind the other, though 
widely distant from it. 
Just as a church-tower, 
two miles off, may ap- 
pear to stand close side /'VEGA 
by side with another 
church-tower two and 
a half miles off, though 
they are in fact sepa- 
rated. Secondly, we 
have the real systems / 
of two suns belonging 
to one another; the 
smaller moving round / ^ 
the larger, or more cor- 1 ,„^---~~ 
rectly both traveling 

round one central point called the center of gravity, 
the smaller having the quicker rate of motion. 

Alpha Centauri and 61 Cygni have been already de- 
scribed, as examples of true double-stars. In the 
constellation Lyra a marked instance is to be seen. 
The brightest star in the Lyre is Vega, and near Vega 
shines a tiny star, which to people with particularly 
clear sight has sometimes rather a longish look. If 
you examine this star through an opera-glass, you find 
it to consist of two separate stars. But if you get a 



/ 



298 STORY OF THE SUN, MOON, AND STARS. 

more powerful telescope, and look again, you will find 
that each star of the couple actually consists of two 
stars. The four are not at equal distances. Two points 
of light seemingly close together are parted by a wide 
gap from two other points equally close together. 
These four stars are believed to have a double motion. 
Each of the separate pairs revolves by itself, the two 
suns traveling round one center; and in addition to 
this the two couples of suns probably perform a long 
journey round another center common to them all. 

Many thousands of double stars have been discov- 
ered; and a large number of these are now known to 
be, not merely two distinct suns lying in the same line 
of sight, but two brother-suns, each probably the cen- 
ter of his own system of planets. 

We have not only to consider the number of suns, 
though of simple numbers more yet remains to be said. 
Attention must also be given to the varying colors of 
different stars ; for all suns in the universe are not 
made after the model of our sun. All suns are not 
yellow. 

So far as single stars are concerned, colors seem 
rather limited. White stars, golden or orange stars, 
ruby-red stars, placed alone, are often seen ; but blue 
stars, green stars, gray stars, silver stars, purple stars, 
are seldom if ever visible to the naked eye, or known 
to exist as single stars. 

Take a powerful telescope and examine star- 
couples, and a very different result you will find. 
Not white, yellow, and red alone, but blue, purple, 
gray, green, fawn, buff, silvery white, and coppery 
hues, will delight you in turn. As a rule, when the 



DIFFERENT KINDS OF SUNS. 299 

two stars of a couple are alike in color, they are 
either white, or yellow, or red. Also in the case of 
double-stars of different colors, the larger of the two 
is almost invariably white or some shade of yellow 
or red. 

There are, however, exceptions to all such rules. 
Blue stars are almost never seen alone, and as one of 
a pair the blue star is generally, if not invariably, the 
smaller. But instances are known of double-stars, 
both of which are blue ; and one group in the south- 
ern heavens is entirely made up of a multitude of 
bluish suns. 

It is when we come to consider double-stars of two 
colors that the most striking effects are found. Now 
and then the two suns are nearly the same in size ; but 
more commonly one is a good deal larger than the other. 
This is known by the brighter light of the largest, and 
the more rapid movements of the smallest. The lesser 
star is often only small by comparison, and may be 
in reality a very goodly and brilliant sun. 

Among nearly six hundred " doubles" examined by 
one astronomer, there were three hundred and sev- 
enty-five in which the two stars were of one color, 
generally white, yellow, orange, or red. The rest were 
different in tint, the difference between the two suns 
in about one hundred and twenty cases being very 
marked. 

For instance, a red "primary," as the larger star is 
called, will be seen with a small green satellite ; or a 
white primary will have a little brother-sun of purple, 
or of dark ruby, or of light red. Sometimes the larger 
sun is orange, the companion being purple or dark 



300 STORY OF THE SUN, MOON, AND STARS. 

blue. Again, the chief star will be red with a blue 
satellite, or yellow with a green satellite, or orange 
with an emerald satellite, or golden with a reddish- 
green satellite. We hear of golden and lilac couples, 




CONSTELLATIONS IN THE NORTHERN HEMISPHERE. 

ot cream and violet pairs, of white and green compan- 
ions. But, indeed, the variety is almost endless. 

There may be worlds circling around these suns — 
worlds, perhaps, with living creatures on them. 
We know little about how such systems of suns and 
worlds may be arranged. Probably each sun would 



DIFFERENT KINDS OF SUNS. 30I 

have his own set of planets, and both snns with their 
planets would travel round one central point. Per- 
haps, where the second sun is much the smallest, it 
might occasionally be like a big blazing satellite among 
the planets — a kind of burning Jupiter-sun to the chief 
sun. 

Among colored stars, single and double, a few may- 
be mentioned by name as examples. Sirius, as al- 
ready observed, is a brilliant white sun ; and brilliant 
white also are Vega, Altair, Regulus, Spica, and many 
others. Capella, Procyon, the Pole-star, and our own sun, 
are examples of yellow stars. Aldebaran, Betelgeuse, 
and Pollux, are ruby-red. Antares is a red star, with 
a greenish " scintillation " or change of hue in its 
twinkling. A tiny green sun belonging to this great 
and brilliant red sun has been discovered. Some have 
called Antares "the Sirius of Red Suns." 

It is during the fine nights of winter that the con- 
stellation Taurus, or The Bull, with the star Alde- 
baran marking its eye, shines in the evening above our 
heads. No other season is so magnificently constel- 
lated as the months of winter. While nature deprives 
us of certain enjoyments in one way, it offers us in 
exchange others no less precious. The marvels of the 
heavens present themselves from Taurus and Orion 
in the east to Virgo and Bootes on the west. Of eigh- 
teen stars of the first magnitude, which are counted in 
the whole extent of the firmament, a dozen are visi- 
ble from nine o'clock to midnight, not to mention 
some fine stars of the second magnitude, remarkable 
nebulae, and celestial objects well worthy of the atten- 
tion of mortals. It is thus that nature establishes an 



302 STORY OF THE SUN, MOON, AND STARS. 

harmonious compensation, and while it darkens our 
short and frosty days of winter, it gives us long nights 
enriched with the most opulent creations of the sky. 
The constellation of Orion is not only the richest in 
brilliant stars, but it conceals for the initiated treas- 
ures which no other is known to afford. We might 
almost call it the California of the sky. 

To the southeast of Orion, on the line of the 
Three Kings, shines the most magnificent of all the 
stars, SzrzuSy or Alpha of the constellation of the Great 
Dog. This constellation rises in the evening at the 
end of November, passes the meridian at midnight 
at the end of January, and sets at the end of March. 
It played the greatest part in Egyptian astronomy, for 
it regulated the ancient calendar. It was the famous 
Dog Star; it predicted the inundation of the Nile, the 
summer solstice, great heats and fevers ; but the pre- 
cession of the equinoxes has in three thousand years 
moved back the time of its appearance by a month and 
a half; and now this fine star announces nothing, 
either to the Egyptians who are dead or to their suc- 
cessors. But we shall see farther on what it teaches 
us of the grandeur of the sidereal universe. 

The Little Dog y or Procyon, is found above the 
Great Dog and below the Twins (Castor and Pollux), 
to the east of Orion. With the exception of Alpha 
Procyon, no brilliant star distinguishes it. 

The two double-stars, 61 Cygni and Alpha Cen- 
tauri, are formed each of two orange suns. 

In the Southern Cross there is a wonderful group 
of stars, consisting of about one hundred and ten 
suns, nearly all invisible to the naked eye. Among the 



DIFFERENT KINDS OF SUNS. . 303 

principal stars of this group, which Sir John Herschel 
described as being, when viewed through a powerful 
telescope, like " a casket of variously-colored precious 
stones," are two red stars, two bright green, three pale 
green, and one of a greenish blue. 

The splendor of these natural illuminations can 
hardly be conceived by our terrestrial imagination. 
The tints which we admire in these stars from here 
can give but a distant idea of the real value of their 
colors. Already, in passing from our foggy latitudes 
to the limpid regions of the tropics, the colors of the 
stars are accentuated, and the sky becomes a veritable 
casket of brilliant gems. What would it be if we 
could transport ourselves beyond the limits of our 
atmosphere? Seen from the moon, these colors would 
be splendid. Antares, Alpha Herculis, Pollux, Alde- 
baran, Betelgeuse, Mars, shine like rubies; the Polar 
Star, Capella, Castor, Arcturus, Procyon, are veritable 
celestial topazes ; while Sirius, Vega, and Altair are 
diamonds, eclipsing all by their dazzling whiteness. 
How would it be if we could approach the stars so as 
to perceive their luminous disks, instead of merely 
seeing brilliant points destitute of all diameter? 

Blue days, violet days, dazzling red days, livid green 
days! Could the imagination of poets, could the ca- 
price of painters, picture on the palette of fancy a 
world of light more astounding than this? Could the 
mad hand of the chimera, throwing on the receptive 
canvas the strange lights of its fancy, erect by chance 
a more astonishing edifice? 



CHAPTER XXV. 

GROUPS AND CLUSTERS OF SUNS. 

WE have been thinking a good deal about single 
stars and double stars, as seen from earth. Now we 
have to turn our attention to groups, clusters, masses 
of stars, in the far regions of space. 

Have you ever noticed on a winter night, when 
the sky was clear and dotted with twinkling stars, a 
band of faintly-glimmering light stretching across the 
heavens from one horizon to the other? The band is 
irregular in shape, sometimes broader, sometimes nar- 
rower; here more bright, there more dim. If you 
were in the Southern Hemisphere you would see the 
same soft belt of light passing all across the southern 
heavens. This band or belt is called the Milky Way. 

But what is the Milky Way? It is made up of 
stars. So much we know. As the astronomer turns 
his telescope to the zone of faintly-gleaming light, he 
finds stars appearing behind stars in countless multi- 
tudes; and the stronger his telescope, the more the 
white light changes into distant stars. 

Our sun we believe to be one of the stars of the 
Milky Way; merely one star among millions of stars ; 
merely one golden grain among the millions of spark- 
ling gold-dust grains scattered lavishly through crea- 
tion. Scattered, not recklessly, not by chance, but 
placed, arranged, and guided each by its Maker's up- 
holding hand. 

304 



GROUPS AND CLUSTERS OF SUNS. 305 

The Milky Way, or the Galaxy, as it has been 
called, has great interest for astronomers. Many have 
been the attempts made to discover its actual size, its 
real shape, how many stars it contains, how far it ex- 
tends ; but to all such questions the only safe answers 
to be returned are fenced around with " perhaps'* and 
" may be." There are many very remarkable clusters of 




A CLUSTER OF STARS IN CENTAURUS. 

stars to be seen in the heavens — some few visible as 
faint spots of light to the naked eye, though the greater 
number are only to be seen through a telescope. 
Either with the naked eye, or in telescopes of varying 
power, they show first as mere glimmers of light, 
which, viewed with a more powerful telescope, sepa- 
rate into clusters of distant stars. 

The most common shape of these clusters is glob- 
ular — to the eye appearing simply round. Stars gather 
20 



306 story of the sun, moon, and stars. 

densely near the center, and gradually open out to 
a thin scattering about the edge. Thousands of suns 
are often thus collected into one cluster. 

The clusters are to be seen in all parts of the sky; 
but the greater number seem to be gathered into the 
space covered by the Milky Way and by the famous 
south Magellanic Clouds. 

Some of them are beautifully colored ; as, for in- 
stance, a cluster in Toucan, not visible from England, 
the center of which is rose-colored, bordered with 
white. No doubt it contains a large number of 
bright red suns, surrounded by a scattering of white 
suns. 

It used to be supposed that many of these clusters 
were other vast gatherings or galaxies of stars, like 
the Milky Way, lying at enormous distances from us. 
This now seems unlikely. The present idea rather is, 
that each cluster, in place of being another "Milky 
Way" of millions of widely-scattered suns, is one 
great star-system, consisting indeed of thousands of 
suns, but all moving round one center. Probably 
most of these clusters are themselves a part of the 
collection of stars to which our sun belongs. 

If this be so, and if worlds are traveling among 
the suns — as may well be, since they are doubtless 
quite far enough apart for each sun to have his own 
little or great system of planets — what sights must be 
seen by the inhabitants of such planets ! 

We do not indeed know the distance between the 
separate suns of a cluster, which may be far greater 
than appears to us. But if astronomers calculate 
rightly, they are near enough together to shed bright 



GROUPS AND CLUSTERS OF SUNS. 307 

light on all sides of a planet revolving in their midst. 
The said planet might perhaps not have within view 
a single sun equal in apparent size to our sun as seen 
from earth; yet thousands of lesser suns, shining 
brightly in the firmament night and day, would cause 
a radiance which we never enjoy. 

No, not night. In such a world there could be no 
night. Worlds in the midst of a star-cluster must be 




the; great nebula in andromeda, compared with 
size of the soi,ar system. 

regions of perpetual day. No night, no starry heaven, 
no sunrise lights or sunset glories, no shadow mingling 
with sunshine, but one continual, ceaseless blaze of 
brightness. We can hardly picture, even in imagina- 
tion, such a condition of things. 

Besides star-clusters there are also nebulae. The 
word nebula comes from the Latin word for "cloud," 
and the nebulae are so named from their cloudlike 
appearance. 

It is not easy to draw a line of clear division be- 



308 STORY OF THE SUN, MOON, AND STARS. 

tween nebulae and distant star-clusters ; for both have 
at first sight the same dim, white, cloudy look. In 
past days the star-clusters were included by astrono- 
mers under the general class of nebulae. And as with 
the star-clusters, so with many of the nebulae, the 
more powerful telescopes of modern days have shown 
them to be great clusters, or systems, or galaxies of 
stars, at vast distances from us. 

It was supposed with the nebulae, as with some of 
the star-clusters, that they were other " Milky Ways" 
of countless stars, far beyond the outside boundaries 
of our Milky Way. This may still be true of some or 
many ntbulae, but certainly not of all. 

For there are different kinds of nebulae. Some 
may, as just said, be vast gatherings of stars lying at 
distances beyond calculation, almost beyond imagina- 
tion. Others appear rather to be clusters of stars, 
like those already described, probably situated in our 
own galaxy of stars. There is also a third kind of 
nebula. Many nebulae, once supposed to be clusters 
of stars, having been lately examined by means of the 
spectroscope, are found to be enormous masses of 
glowing gas, and not solid bodies at all. 

The number of nebulae known amounts to many 
thousands. They are commonly divided into classes, 
according to their seeming shape. There are nebulae 
of regular form, and nebulae of irregular form. There 
are circular nebulae, oval nebulae, annular nebulae, 
conical nebulae, cometary nebulae, spiral nebulae, and 
nebulae of every imaginable description. These 
shapes would no doubt entirely change, if we could 
see them nearer; and indeed, even in more power- 



GROUPS AND CLUSTERS OF SUNS. 309 

ful telescopes, they are often found to look quite differ- 
ent. While on the subject of clusters and nebulae, men- 
tion should be made of the famous Magellanic Clouds 
in the southern heavens. Sometimes they are called 
the Cape Clouds. They differ from other nebulae in 
many points, and more particularly in their apparent 
size. The Great Cloud is about two hundred times 
the size of the full moon, while the Small Cloud is 
about one-quarter as large. In appearance they are 
not unlike two patches of the Milky Way, separated 
and moved to a distance from the main stream. 

These clouds are surrounded by a very barren por- 
tion of the heavens, containing few stars; but in 
themselves they are peculiarly rich. Seen through a 
powerful telescope, they are found to abound with 
stars. The Greater Cloud alone contains over six 
hundred from the seventh to the tenth magnitudes, 
countless tiny star-points of lesser magnitudes, star- 
clusters of all descriptions, and nearly three hundred 
nebulae, — all crowded into this seemingly limited 
space. 

Among many famous nebulae, the one in Orion and 
the one in Andromeda may be particularly mentioned. 
The size of the latter, as compared with the size of 
our Solar System, is shown in the cut of this nebula. 
On the hypothesis of a complete resolvability into stars, 
the mind is lost in numbering the myriads of suns, the 
agglomerated individual lights of which produce these 
nebulous fringes of such different intensities. What 
must be the extent of this universe, of which each sun 
is no more than a grain of luminous dust! 



CHAPTER XXVI. 

THE PROBLEM OF SUN AND STAR DISTANCES. 

One question had long occupied the minds of sci- 
entific men without the finding of any satisfactory 
answer, and this was the distance of the sun from 
our earth. 

At length the sun had fully gained his rightful po- 
sition in the minds of men as center and controller of 
the Solar System, and earth was fully dethroned from 
her old false position. In point of fact, the sun had 
gained more than his rightful position; since he was 
now looked upon very much as the earth had been 
formerly looked upon; since he was regarded prac- 
tically as the motionless Universe-Center. The earth 
might and did move — people had grown used to that 
idea — but the sun, at all events, was fixed. The sun, 
beyond turning upon his axis, was motionless. 

Still, as to the true distance of the sun from ourselves, 
ignorance reigned. Tycho Brahe had made a great 
advance on earlier notions by placing the light-giver 
4,000,000 miles away in imagination. Kepler, a 
quarter of a century later, increased this to 14,000,- 
000. Galileo afterwards reverted to the 4,000,000. 
All this, however, was sheer guesswork. 

Not till well on in the seventeenth century did Cas- 
sini make a definite attempt at actual measurement of 
the sun's distance, and this attempt gave as a result 
some 82,000,000 miles — not far removed from the 

310 



SUN AND STAR DISTANCES. 3II 

truth. But at the same period other observers gave 
results of 41,000,000 and 136,000,000; so for years 
the question still remained swathed in mist. Better 
modes and better instruments were required before it 
could receive settlement. 

The measurement of the distance of objects a good 
way off is by means of their " parallax," or the appar- 
ent change in their position when viewed from two 
different points at some distance from each other. 
To this method of calculating distance we have al- 
ready referred. 

This kind of measurement of distances is not con- 
fined to our earth's surface alone. The distances of 
bright bodies in the heavens may be calculated after 
just the same method, provided only that the heavenly 
body is not too far distant to be made to change its 
seeming position in the sky. 

Suppose you wished to find out how far off the 
moon is. You would have to make your observation 
of the moon's exact position in the sky — of just that 
spot precisely where she is to be seen among heavenly 
scenery at a particular moment ; and you would have 
to get somebody else to make a similar observation, at 
the same time, from some other part of earth, at a 
good distance from your post. 

There are no hills or woods in the sky for the moon 
to be seen against; but there are plenty of stars, bright 
points of light far beyond the moon. If you look at 
her from one place, and your friend looks at her from 
another place a good way off, there will be a differ- 
ence in your two " views." You will see her very 
close to certain stars; and your friend will see her not 



312 STORY of the; sun, moon, and stars. 

quite so close to those stars, but closer to others. This 
difference of view would give the moon's parallax. 

If your observation were very careful, very exact, 
and if you had the precise distance between the spot 
where you stood, and the spot where your friend stood, 
— then, from that base-line, and from the two angles 
formed by its junction with the lines from the two 
ends of it straight to the moon, you might reckon 
how many miles away the moon is. The greater the 
distance between the two places of observation, the 
better, — as, for instance, at Greenwich and the Cape 
of Good Hope. 

Practically, this is not nearly so simple a matter as 
it may sound, because our earth is always on the move, 
and the moon herself is perpetually journeying onward. 
All such motions have to be most scrupulously allowed 
for. So the actual measurement of moon-distance re- 
quires a great deal of knowledge and of study. Many 
other difficulties and complications besides these enter 
into the question, and have to be overcome. 

Now, the sun is very much farther away than the 
moon, and the stumbling-blocks in the way of find- 
ing out his distance become proportionately greater 
and more numerous. To observe him from two parts 
of England, or from two parts of Europe, would give 
him no parallax. That is to say, there would be no 
change of position on his part apparent to us. 

I do not say that there would be no change at all; 
but only that it would be so minute as to be quite un- 
seen by human eyes, even with the help of most care- 
ful and accurate measurement. A very long base-line 
is needed to make the sun distinctly appear to change 



SUN AND STAR DISTANCES. 313 

his position ever so little. Only the very longest 
base-line which can be fonnd on earth will do for 
this, — nothing less than the earth's whole diameter 
of nearly eight thousand miles. And I think you 
will see that the success of the calculation would 
then depend, not alone on most careful observation 
from two posts at the opposite sides of earth ; not 
alone on mathematical gifts and powers of close reck- 
oning; but also, essentially, on a true knowledge of 
our earth's diameter ; that is, of the exact length of 
the base-line from which the whole calculation would 
have to be made, and upon which the answer would 
largely depend. 

For a long while the earths diameter was not well 
known. As time went on, fresh measurements were 
again and again made of different portions of earth's 
surface, fresh calculations following therefrom ; and 
gradually clear conclusions were reached. A very 
important matter it was that they should be reached ; 
for the semi-diameter of our earth has been adopted 
as a " standard measure" for the whole universe ; and 
the slightest error in that standard measure would 
affect all after calculations. 

When actual observations of sun-distance came to be 
made, innumerable difficulties arose. Foremost stood 
the huge amount of that distance. This made pre- 
cise observations more- difficult; and at the same time 
it made every mistake in observation so much the 
worse. A little mistake in observing the moon 
might mean only a hundred miles or so wrong in the 
answer; but a mistake equally small in observing the 
sun would lead to an error of many millions of miles. 



314 STORY OF THE SUN, MOON, AND STARS. 

Again, to observe the sun's exact position among 
the stars, as with the moon, was not possible ; because 
when the sun is visible, the stars are not visible. 
Then, too, the dazzling brightness of the sun balked 
the needed exactitude. 

Halley had a brilliant thought before he died. He 
could not carry it out himself, but he left it to others 
as a legacy; that was, by observing the transit of 
Venus from two different points on the earth's sur- 
face. At his suggestion, on the first opportunity — 
which was not till after his death — the above mode 
was tried of measuring the sun's distance. 

A certain observer, stationed on one part of earth, 
saw the tiny dark body of Venus take one particular 
line across the sun's bright face. Another observer, 
standing on quite another and a far-off part of earth, 
saw the little dark body take quite another line across 
the sun's bright face. Not that there were two little 
dark bodies, but that the one body was seen by differ- 
ent men in different places. 

From these separate views of the path of Venus 
across the face of the sun, in connection with what 
was already known of the earth's diameter, and there- 
fore of the length of base-line between the two places, 
the distance of the sun was reckoned to be about 95- 
000,000 miles. 

Since that date many fresh attempts have been 
made, and errors have been set right. Mercury as 
well as Venus has been used in this matter, and other 
newer modes of measurement have also been success- 
fully tried. We know now, with tolerable accuracy, 
that the sun's greater distance from earth is between 



SUN AND STAR DISTANCES. 315 

92,000,000 and 93,000,000 miles. A curious illustra- 
tion of sun-distance has been offered by one writer. 
Sound and light, heat and sensation, all require time 
for journeying. When a child puts his finger into a 
candle-flame, he immediately shrieks with pain. Yet, 
quickly as the cry follows the action, his brain is not 
really aware of the burn until a certain interval has 
elapsed. True, the interval is extremely minute ; still 
it is a real interval. News of the burn has to be tele- 
graphed from the finger, through the nerves of the 
arm, up to the brain ; and it occupies time in trans- 
mission, though so small a fraction of a second that 
we can not be conscious of it. 

Now, try to imagine a child on earth with an arm 
long enough to reach the sun. His fingers might be 
scorched by the raging fires there, while yet his brain 
on earth would remain quite unaware of the fact for 
about one hundred and thirty years. All through 
those years, sensation would be darting along the 
arm exactly as fast as it darts from the finger-tips of 
an ordinary child on earth to that child's brain. 

If the scorching began before he was one year old, 
he would have become a very aged man, one hundred 
and thirty years old, before he could know in his mind 
what was happening in the region of his hand. More- 
over, if, on receiving the intimation, he should decide 
to withdraw his hand from that unpleasantly-hot 
neighborhood, another hundred and thirty years would 
elapse before the fingers could receive and act upon 
the message, telegraphed from the brain, through the 
nerves of the arm. So much for the distance of the 
sun from our earth ! 



316 STORY OF THE SUN, MOON, AND STARS. 

But the stars! How far off are the stars? 

The distance of the moon is a mere nothing. The 
distances of the planets have been found out. The 
distance of the sun has been measured. But the 
stars — those wondrous points of light, twinkling on, 
night after night, century after century, unchanged in 
position save by the seeming nightly pilgrimage of 
them all across the sky in company, caused only by 
our earth's restless, continual whirl, — 

What about the distances of the stars? Can we 
measure their distance by means of their parallax? 
This mode of measurement was tried successfully on 
the moon, on the planets, and on the sun. But when 
it was tried upon the stars, from two stations as far 
apart as any two stations on earth could be, the at- 
tempt was a failure. Not a ghost of parallax could 
be detected with any one star. Not the faintest sign 
of displacement was seen in the position of a single 
star when most critically and carefully examined. 

Then arose a brilliant thought! What of earth's 
yearly journey round the sun? If a base-line of 8,000 
miles were not enough, compared with the great dis- 
tance of the stars, this at least remained. Our earth 
at midsummer is somewhere about 185,000,000 miles 
away from where she is at midwinter, comparing her 
position with that of the sun, and reckoning him to 
be at rest. 

In reality, the sun is not at rest, but is in ceaseless 
motion, carrying with him, wherever he goes, the 
whole Solar System with as much ease as a train 
carries its passengers. Those passengers are truly in 
motion, yet, with regard merely to the train, they are 



SUN AND STAR DISTANCES. 317 

at rest. So each member of the Solar System — at- 
tached to the sun, not by Ptolemaic bars, but by the 
bond of gravity — is borne along by him through 
space; yet, with respect to each member of that sys- 
tem, the central sun is always and absolutely at rest. 

At one time of the year, our earth is on one side of 
the sun, over 92,000,000 miles distant. Six months 
later, the earth is on the other side of the sun, not 
quite 93,000,000 miles away from him in that oppo- 
site direction. Twice 93,000,000 comes to 186,000,000. 
This line, therefore — the diameter of the earth's whole 
yearly orbit, may be roughly stated as about 185,000,- 
000 of miles in length. 

Here surely was a base-line fit to give parallax to 
any star — or, rather, to make parallax visible in the 
case of any star. For it is, after all, a question, not of 
fact, but of visibility ; not of whether the thing is, but 
of whether we are able to see it. 

As the earth journeys on her annual tour round the 
sun, following a slightly elliptic pathway, the diameter 
of which is about 185,000,000 miles, each star in the 
sky must of necessity undergo a change of position, 
however minute, performing a tiny apparent annual 
journey in exact correspondence with the earth's great 
annual journey. 

The question is not, Does the star do this? but, 
Can we see the star do this? Its apparent change of 
position may be so infinitesimal, through enormous 
distance, that no telescopes or instruments yet made 
by man can possibly show it to us. 

The star-motion of which I am now speaking is 
purely a seeming movement, not real. Be very clear 



318 STORY OF THE SUN, MOON, AND STARS. 

on this point in your mind. Real star-movements, 
though suspected earlier, were not definitely surmised 
— one may even say "discovered" — until the year 
1 718, by Halley. And though Cassini in 1728 re- 
ferred to this discovery of Halley's, yet very little was 
heard about the matter until the days of Herschel. 
Only apparent star-motions were generally understood 
and accepted. 

The first and simplest of such seeming star-motions 
is one which we can all see- — the nightly journey of 
the whole host of stars, caused by our earth's whirl 
upon her axis. 

The second is also simple, but by no means also 
easily seen. Astronomers reasoned out the logical 
necessity for such an apparent motion long before it 
could be perceived. As far back as the days of Co- 
pernicus it was felt that if the Copernican System 
were true, if the earth in very deed traveled round 
the sun, then the stars ought to change their positions 
in the sky when viewed from different parts of earth's 
annual journey. Observations were taken, divided by 
six months of time and by one hundred and eighty- 
five millions ot miles of space. And the stars 
stirred not! 

Stupendous as was this base-line, it proved insuffi- 
cient. So much more stupendous was the distance of 
the stars that the base-line sank to nothing, and once 
again parallax could not be detected. Not that the 
seeming change of position in the star did not take 
place, but that human eyes were unable to see it, 
human instruments were unable to register it. 

There lies the gist of the matter. If the change 



SUN AND STAR DISTANCES. 319 

of position can be observed, well and good! The 
length of the base-line being known, the distance of 
the star may be mathematically calculated. For the 
size of the tiny apparent path, followed in a year by 
the star, is and must be exactly proportioned to the 
distance of the star from that base-line. If the tiny 
oval be so much larger, then the star is known to be 
so much nearer. If the tiny oval be so much smaller, 
then the star is known to be so much farther away. 

But when not the minutest token could be discov- 
ered of a star's position in the sky being in the least 
degree affected by the earth's great annual change of 
position, astronomers were at a loss. There was ab- 
solutely nothing to calculate from. The star was a 
motionless point to earth. The whole yearly orbit of 
earth was a motionless point to the star. One slen- 
der beam of light united the two. Reckoners had 
nothing to stand upon. 

It is interesting to know that Copernicus had ac- 
tually, long before, suggested this as a possible ex- 
planation of the absence of star-parallax. He thought 
that astronomers might fail altogether to find it, be- 
cause the stars might be " at a practically infinite dis- 
tance" from our earth. 



CHAPTER XXVII. 

MEASUREMENT OF STAR DISTANCES. 

Unti^ the days of Sir William Herschel, little at- 
tention was bestowed upon the universe of distant stars. 
Before his advent the interest of astronomers had been 
mainly centered in the sun and his revolving worlds. 
The " fixed stars" were indeed studied, as such, with 
a certain amount of care, and numberless efforts were 
made to discover their distances from earth; but the 
thought of a vast Starry System, in which our little 
Solar System should sink to a mere point by compar- 
son with its immensity, had not yet dawned. 

With larger and yet larger telescopes of his own 
making, Herschel studied the whole Solar System, and 
especially the nature of sun-spots, the rings of Saturn, 
the various motions of attendant moons, together 
with countless other details. He enlarged the system 
by the discovery of another planet outside Saturn — the 
planet Uranus, till then unknown. 

These were only first steps. The work which he 
did in respect of the Solar System was as nothing 
compared with the work which he did among the 
stars. His work in our system was supplementary to 
other men's labors; his work among the stars was the 
beginning of a new era. Like many before him, he, 
too, sought eagerly to find star-parallax, and he, too, 
failed. Not yet had instruments reached a degree of 

320 



MEASUREMENT OE STAR DISTANCES. 32 1 

finish which should permit measuring operations of 
so delicate a nature. 

Although he might not detect star-parallax, he 
sprang a mine upon the older notions of star-fixity. He 
shook to its very foundations the sidereal astronomy of 
the day, — the theory, long held, of a motionless uni- 
verse, motionless stars, and a rotating but otherwise 
motionless sun. He did away with the mental pic- 
ture, then widely believed in, of vast interminable fix- 
ity and stillness, extending through space, varied only 
by a few little wandering worlds. As he swept the 
skies, and endeavored to gauge the fathomless depths, 
and vainly pursued the search for the parallax of one 
star after another, he made a great and unlooked- 
for discovery. This was in connection with double- 
stars. 

Double-stars had long been known, and were gen- 
erally recognized. But whether the doubleness were 
purely accidental, due merely to the fact of two stars 
happening to lie almost in the same line of sight, as 
viewed from earth, or whether any real connection 
existed between the two, no man living could say. 
Indeed, so long as all stars were regarded as utter 
fixtures, the question was of no very great interest. 

But light dawned as Herschel watched. He found 
the separate stars in a certain pair to be moving. 
Each from time to time had slightly, very slightly, 
changed its place. Then, at least, if all other stars in 
the universe were fixed, those two were not fixed. He 
watched on, and gradually he made out that their mo- 
tions were steady, were systematic, and were connected 
the one with the other. That was one of the first 



322 STORY OF THE SUN, MOON, AND STARS. 

steps towards breaking down the olden notion, so 
widely held, of a fixed and unchanging universe. 

Another double-star, and yet another, responded to 
Herschel's intense and careful searching. These other 
couples, too, were revolving, not separately, but in 
company; journeying together round one center; 
bound together apparently by bonds of gravitation, 
even as our sun and his planets are bound together. 

Other stars besides binary stars are found to move 
with a real and not merely a seeming movement. 
Viewed carelessly, the stars do indeed appear to re- 
main fixed in changeless groups ; fixed even through 
centuries. But, to exceedingly close watching and 
accurate measurement, many among them are dis- 
tinctly not fixed ; many among them can be actually 
seen to move. 

Of course the observed motions are very small and 
slow. One may be found to creep over a space as 
wide as the whole full moon in the course of three 
hundred or four hundred years; and this is rapid trav- 
eling for a star in earth's sky! Another will perhaps 
cross a space one-tenth or one-twentieth or one-fiftieth 
of the moon's width in one hundred years. 

Such motions had never been carefully noted or 
examined, until Herschel came to do away with 
the old received notions of star-fixity. Happily, 
Herschel was no slave to "received ideas." Like 
Galileo in earlier times, he wished to "prove all 
things'* personally, anxious only to find out what 
was the truth. And he found that the stars were not 
fixed! He found that numbers of them were mov- 
ing. He conjectured that probably all the rest were 



MEASUREMENT OF STAR DISTANCES. 323 

moving also; that in place of a fixed universe of 
changeless stars we have a whirling universe of rush- 
ing suns. 

Herschel could not, of course, watch any one star 
for a hundred years, much less for several centuries. 
But in a very few years he could, by exceedingly close 
measurement, detect sufficient motion to be able to 
calculate how long it would take a certain star to creep 
across a space as wide as the full moon. 

From step to step he passed on, never weary of his 
toil. He sought to gauge the Milky Way, and to form 
some notion of its shape. He noted a general drift of 
stars to right and to left, which seemed to speak of a 
possible journey of our sun through space, with all 
the planets of the Solar System. He flung himself 
with ardor into the study of star-clusters and of neb- 
ulae. He saw, with an almost prophetic eye, the 
wondrous picture of a developing universe — of nebulae 
growing slowly into suns, and of suns cooling gradu- 
ally into worlds — so far as to liken the heavens to a 
piece of ground, containing trees and plants in every 
separate stage of growth. 

And still the search for star parallax went on, so 
long pursued in vain. No longer base-line than that 
of the diameter of earth's yearly orbit lay within man's 
reach. But again and yet again the attempt was 
made. Instruments were improved, and measure- 
ments became ever more delicate ; and at length some 
small success crowned these persistent endeavors. The 
tiny sounding-line of earth, lowered so often into the 
mysterious depths of space, did at last "touch bottom." 

Herschel died, full of years and honors, in 1822; 



324 STORY OF THE SUN, MOON, AND STARS. 

and some ten years later three different attempts 
proved, all to some extent, and almost at the same 
date, successful. Bessel, however, was actually the 
first in point of time; and his attempt was upon the 
double-star, 61 Cygni; not at all a bright star, but only 
just visible to the naked eye. 

There are stars and stars, enough to choose from. 
The difficulty always was, which to select as a subject 
for trial with any reasonable prospect of a good result. 
Some astronomers held that the brightest stars were the 
most hopeful, since they were probably the nearest; 
and of course the nearer stars would show parallax 
more readily, because their parallax would be the 
greater. But certain very bright stars indeed are 
now known to be far more distant than certain very 
dim stars. 

Again, some astronomers thought that such stars 
as could be perceived to move most rapidly in the 
course of years would be the most hopeful objects to 
attack, since the more rapid movement might be sup- 
posed to mean greater nearness, and so greater ease 
of measurement. But some stars, seen to move rap- 
idly, are now known to be more distant than others 
which are seen to move more sluggishly. So neither 
of these two rules could altogether be depended on; 
yet both were, on the whole, the best that could be 
followed, either separately or together. 

The star 61 Cygni is not one of the brighter stars, 
but it is one of those stars which can be seen to travel 
most quickly across the sky in the course of a cen- 
tury. Therefore it was selected for a trial ; and that 
trial was the first to meet with success. 



MEASUREMENT OF STAR DISTANCES. 325 

For 61 Cygni was found to have an apparent paral- 
lax; in other words, its tiny seeming journey through 
the year, caused by our earth's great journey round 
the sun, could be detected. Small as the star-motion 
was, it might, through careful measurement, be per- 
ceived. And, in consquence, the distance of the star 
from earth could be measured. Not measured with 
anything like such exactitude as the measurements of 
sun-distance, but with enough to give a fair general 
notion of star-distance. 

One success was speedily followed by others. By 
a few others, — not by many. Among the thousands of 
stars which can be seen by the naked eye, one here and 
one there responded faintly to the efforts made. One 
here and one there was found to stir slightly in the 
sky, when viewed from earth's summer and winter 
positions, or from her spring and autumn positions, in 
her yearly pathway round the sun. 

It was a very, very delicate stir on the part of the 
star. Somewhat like the difference in position which 
you might see in a penny a few miles off, if you looked 
at it first out of one window and then out of another 
window in the same house. You may picture the 
penny as radiantly bright, shining through pitch dark- 
ness; and you may picture yourself as looking at it 
through a telescope. But even so, the apparent change 
of position in the penny, viewed thus, would be exceed- 
ingly minute, and exceedingly difficult to see. 

There are two ways of noting this little seeming 
movement on the part of a star in the sky. 

Either its precise place in the sky may be ob- 
served — its exact position, as in a map of the heavens 



326 STORY OF THK SUN, MOON, AND STARS. 

— or else its place may be noted as compared with an- 
other more distant star, near to it in the sky, though 
really far beyond. Parallax, if visible, would make it 
alter its precise place in the sky. Parallax, if visible, 
would bring it nearer to or farther from any other 
star more distant than itself from earth. The more 
distant star would have a much smaller parallax — 
probably so small as to be invisible to us — and so it 
would do nicely for a " comparison star." 

The first of these methods was the first tried ; and 
the second was the first successful. 

To find star-distance through star-parallax sounds 
quite simple, when one thinks of the general principle 
of it. Just merely the question of a base-line, accurately 
measured; and of two angles, accurately observed; 
and of another angle, a good way off, accurately cal- 
culated, — all resting on the slight seeming change of 
position in a certain distant object, watched from two 
different positions, about 185,000,000 miles apart. 

Quite simple, is it not? Only, when one comes to 
realize that the "change of position" is about equal 
to the change of position in a penny piece, miles away, 
looked at from two windows in one house, — then the 
difficulty grows. 

Besides this, one has to remember all the "cor- 
rections" necessary, before any true result can be 
reached. 

A penny piece, miles away, seen from two win- 
dows, would be difficult enough as a subject for meas- 
urement. But, at least, the penny would be at rest ; and 
you yourself would be at rest ; and light would pass 
instantaneously from it to you ; and there would be no 



MEASUREMENT OF STAR DISTANCES. 327 

wobbling and nodding motions of everything aronnd 
to add to your perplexities. 

In the measurement of star-parallax, all these 
things have to be considered and allowed for ; all have 
to be put out of the question, as it were, before any 
correct answer is obtained. 

The refraction of light must be considered ; because 
that displaces the star, and makes it seem to us to be 
where it is not. And the aberration of light must be 
considered; because, in a different way, that does the 
same thing, making the star seem to take a little jour- 
ney in the course of the year. And the precession, or 
forward motion, of the equinoxes, and nutation, or 
vibratory motion, have both to be separately con- 
sidered ; because they, too, affect the apparent position 
of every star in the sky. 

To watch the star in comparison with another star 
is easier than merely to note its exact position in the 
sky; for the other star — the " companion-star " — is 
equally with itself affected by refraction of light and 
by aberration of light. But, then, another question 
comes in seriously: whether or no the companion-star 
shows any parallax also ; since, if it does, that paral- 
lax must be carefully calculated and allowed for. 

So the measurement of star-distance, even when 
parallax can be detected, is by no means a light or 
easy matter. On the contrary, it bristles with diffi- 
culties. It is a most complicated operation, needing 
profound knowledge, accurate observation, trained 
powers of reasoning and calculation. 

Nothing short of what has been termed " the ter- 
rific accuracy" of the present day could grapple with 



328 STORY OF THE SUN, MOON, AND STARS. 

the truly tremendous difficulties of this problem of star- 
distance. It has, however, been grappled with, and 
grappled with successfully. We now know, not in- 
deed with anything like exactitude, yet with reason- 
able certainty, the distances of a good many stars, as 
expressed roughly in round number of " about' ' so 
many trillions of miles.* We have at least learned 
enough to gain some notion of the immeasurable dis- 
tances of countless other stars, lying far beyond reach 
of earth's longest measuring-line. 

The very thought of such unimaginable depths of 
space, of suns beyond suns "in endless range," toned 
down by simple distance to mere quivering specks of 
light, is well-nigh overwhelming. 



*The diameter of the moon as seen from the earth is equal to one thousand 
eight hundred and sixty eight seconds of space. When the parallax of a star 
is ascertained, it is a simple matter to calculate the distance of the star by the 
use of the following table. If the star shows a displacement of one second in 
space, or one eighteen-hundred-and-sixty-eighth part of the width of the moon, 
that star is distant two hundred and six thousand two hundred ana sixty-five 
times the distance of the earth from the sun. 

An angle of i" is equivalent to 206,265 times 93,000,000 of miles. 
" " " o".9 " " " 229,183 " 



o".8 " 


" 257,830 " 


o".7 " 


" 294,664 " 


o".6 " 


" 343.750 


o"-5 " 


" 412,530 " 


o". 4 " 


" 515-660 " 


o". 3 " 


" 687,500 " 


o",2 " 


" 1,031,320 " 


c".i " 


" 2,062,650 " 


o".o " 


" Immeasurable 



The nearest star, Alpha Centauri, shows a parallax of less than one second 
(o".75). The farthest star, the distance of which has been ascertained, is 1830- 
Groombridge, which shows a parallax of only o".o45, and is distant 4,583,000 
times earth's distance from the sun, or 426 trillions of miles. 



CHAPTER XXVIII. 

THE MILKY WAY. 

The Milky Way forms a soft band of light round 
the whole heavens. In the Southern Hemisphere, as 
in the Northern Hemisphere, it is to be seen. In some 
parts the band narrows ; in some parts it widens. Here 
it divides into two branches ; there we find dark spaces 
in its midst. One such space in the south is so black 
and almost starless as to have been named the Coal- 
sack. All along, over the background of soft, dim 
light, lies a scattering of brighter stars shining on its 
surface. Much interest and curiosity have long been felt 
about this mysterious Milky Way. That it consists 
of innumerable suns, and that our sun is one among 
them, has been believed for a considerable time. But 
other questions arise. How many stars does the 
Milky Way contain? What is its shape? How far 
does it reach? 

No harm in asking the questions, only we have to 
be satisfied in astronomy to ask many questions which 
can not yet receive answers. No harm for man to 
learn that the utmost reach of his intellect must fall 
short in any attempt to sound the depths of God's 
universe, even as the arm of a child would fall short 
in seeking to sound the depths of the ocean over the 
side of a little boat. For the attempt has been made 
to sound the depths of our star-galaxy out of this little 
earth-boat. 

329 



330 STORY OF THE SUN, MOON, AND STARS. 

The idea first occurred to trie great Herschel, as 
we have already mentioned, and a grand idea it was — 
only a hopeless one. He turned his powerful tele- 
scope north, south, east, west. He counted the stars 
visible at one time in this, in that, in the other direc- 
tions. He found a marked difference in the numbers. 
The portion of sky seen through his telescope was 
about one quarter the size of that covered by the 
moon. Sometimes he could merely perceive two or 
three bright points on a black background. At other 
times the field of his telescope was crowded. In the 
fuller portions of the Milky Way, he had four or five 
hundred stars under view at once. In one place he 
saw about one hundred and sixteen thousand stars 
pass before him in a single quarter of an hour. 

Herschel took it for granted that the stars of the 
Milky Way, uncountable in numbers, are, as a rule, 
much the same in size — so that brightest stars would, 
as a rule, be nearest, and dimmest stars would, as a 
rule, be farthest off. Where he found stars clustering 
thickly, beyond his power to penetrate, he believed 
that the Milky Way reached very far in that direc- 
tion. Where he found black space, unlighted by stars 
or lighted by few stars, he decided that he had found 
the borders of our galaxy in that direction. 

Following these rules which he had laid down, he 
made a sort of rough sketch of what he supposed 
might be the shape of the Milky Way. He thought 
it was somewhat flat, extending to a good distance 
breadthways and a much greater distance lengthways, 
and he placed our sun not far from the middle. This 
imagined shape of the Milky Way is called "The 



THE MILKY WAY. 33I 

Cloven-disk Theory." To explain the appearance of 
the Milky Way in the sky, Herschel supposed it to be 
cloven or split through half of its length, with a black 
space between the two split parts. 

It seems that Herschel did not hold strongly to 
this idea in later years, and doubts are now felt 
whether the rules on which he formed it have suffi- 
cient foundation. 

For how do we know that the stars of the Milky 
Way are, as a rule, much the same in size? Certainly 
the planets of the Solar System are very far from be- 
ing uniform, and the few stars whose weight can with 
any certainty be measured, seem to vary considerably. 
There is a great difference also between the large and 
small suns in many of the double-stars ! 

Again, how do we know that the bright stars are, 
as a rule, the nearest, and the dim stars the farthest 
off? Here, also, late discoveries make us doubtful. 
Look at Sirius and 61 Cygni — Sirius the most radiant 
star in the heavens, and 61 Cygni almost invisible to 
the naked eye. According to this rule, 61 Cygni 
ought to lie at an enormous distance beyond Sirius. 
Yet in actual fact, Sirius is the farthest away of 
the two. 

The illustrious Herschel believed that he had pene- 
trated, on one occasion, into the star-cluster on the 
sword-hand in the constellation ot Perseus until he 
found himself among siderial depths, from which the 
light could not have reached him in less than four 
thousand years. 

The distance of those stars had not, and has not, 
been mathematically measured. Herschel judged of 



332 STORY OP THE SUN, MOON, AND STARS. 

it by their dimness, by the strong power needed to 
make them visible, and by the rules which he had 
adopted as most likely true. 

Again, when Herschel found black spaces in the 
heavens almost void of stars, and believed that he 
had reached the outside borders of the Milky Way, 
he may have been in the right, or he may have been 




A CLUSTER OF STARS IN PERSEUS. 

mistakeno The limit might lie there, or thousands 
more of small stars might extend in that very direc- 
tion, too far off for their little glimmer to be seen 
through the most powerful telescope. 

If this latter idea about the Milky Way being 
formed of a great many brilliant suns, and of vast 
numbers of lesser suns also, be true, astronomers 



the milky way. 333 

will, in time, be able to prove its truth. For in that 
case, many faint telescopic stars being much nearer 
to us than bright stars of the greater magnitudes, it 
will be found possible to measure their distance. 
The journey of our earth round the sun must cause 
a seeming change in their position between summer 
and winter. 

The theory also that some of the nebulae are other 
outlying Milky Ways, or galaxies of stars, separated 
by tremendous distances from our own, is interesting, 
and was long held as almost certain, yet we have no 
distinct proof either one way or the other. Many of 
the nebulae may be such gatherings of countless stars 
outside our own, or every nebula visible may be ac- 
tually part and parcel of our galaxy. 

Much attention has of late been paid to the ar- 
rangement of stars in the sky. The more the matter 
is looked into, the more plainly it is seen that stars 
are neither regular in size nor regular in distribution. 
They are not merely scattered carelessly, as it were, 
here, there, and anywhere, but certain laws and plans 
of arrangement seem to have been followed which 
astronomers are only now beginning dimly to perceive. 

Stars are not flung broadcast through the heavens, 
each one alone and independent of the rest. They 
are placed often, as we have already seen, in pairs, in 
triplets, in quartets, in clusters. Also, the great masses 
of them in the heavens seem to be more or less ar- 
ranged in streams, and sprays, and spirals. So remark- 
able are the numbers and forms of many of these 
streams that the idea has been suggested, with regard 
to the Milky Way, whether it also may not be a vast 



334 STORY OF THE SUN, MOON, AND STARS. 

stream of stars, like a mighty river, collecting into it- 
self hundreds of lesser streams. 

The contemplation of the heavens affords no spec- 
tacle so grand and so eloquent as that of a cluster of 
stars. Most of them lie at such a distance that the 
most powerful telescopes still show them to us like 
star-dust. "Their distance from us is such that they 
are beyond, not only all our means of measurement,'' 
says Newcomb, "but beyond all our powers of estima- 
tion. Minute as they appear, there is nothing that we 
know of to prevent our supposing each of them to be 
the center of a group of planets as extensive as our 
own, and each planet to be as full of inhabitants as 
this one. We may thus think of them as little colo- 
nies on the outskirts of creation itself, and as we see 
all the suns which give them light condensed into one 
little speck, we might be led to think of the inhabit- 
ants of the various systems as holding intercourse with 
each other. Yet, were we transported to one of these 
distant clusters, and stationed on a planet circling one 
of the suns which compose it, instead of finding the 
neighboring suns in close proximity, we should see a 
firmament of stars around us, such as we see from the 
earth. Probably it would be a brighter firmament, in 
which so many stars would glow, with more than the 
splendor of Sirius, as to make the night far brighter 
than ours; but the inhabitants of the neighboring 
worlds would as completely elude telescopic vision as 
the inhabitants of Mars do. here. Consequently, to 
the inhabitants of every planet in the cluster, the ques- 
tion of the plurality of worlds might be as insolvable 
as it is to us." 



THE MILKY WAY. 335 

These are clusters of stars of regular form in which 
attraction appears to mark its secular stamp. Our 
mind, accustomed to order in the cosmos, anxious for 
harmony in the organization of things, is satisfied with 
these agglomerations of suns, with these distant uni- 
verses, which realize in their entirety an aspect ap- 
proaching the spherical form. More extraordinary, 
more marvelous still, are the clusters of stars which 
appear organized in spirals. 

In considering stars of the first six magnitudes 
only — stars visible to the naked eye — a somewhat 
larger number is found in the Southern Hemisphere 
than in the Northern Hemisphere. In both hemi- 
spheres there are regions densely crowded with stars, 
and regions by comparison almost empty. 

It has been long questioned whether the number 
of bright stars is or is not greater in the Milky Way 
than in other parts of the sky. Careful calculations 
have at length been made. It appears that the whole 
of the Milky Way — that zone of soft light passing 
round the earth — covers, if we leave out the Coal-sack 
and other such gaps, between one-tenth and one-elev- 
enth of the whole heavens. 

The entire number of naked-eye stars, or stars of 
the first six magnitudes, does not exceed six thousand; 
and of these, eleven hundred and fifteen lie scattered 
along the bed of the Milky Way stream. If the 
brighter stars were scattered over all the sky as thickly 
as throughout the Milky Way, their number would 
amount to twelve thousand instead of only six thou- 
sand„ This shows us that the higher-magnitude stars 
really are collected along the Milky Way in greater 



336 STORY OF TH£ SUN, MOON, AND STARS. 

numbers than elsewhere, and is an argument used by 
those who believe the Milky Way to be a mighty 
stream of streams of stars. 

In the dark spaces of the Milky Way, on the con- 
trary, bright stars are so few that if they were scat- 
tered in the same manner over all the sky, their pres- 
ent number of six thousand would come down to 
twelve hundred and forty. This would be a seri- 
ous loss. 

We know in the sky 1,034 clusters of stars and 
more than 11,000 nebulae. The former are composed 
of associated stars ; the latter may be divided into two 
classes: First, nebulae which the ever-increasing prog- 
ress of optics will one day resolve into stars, or which 
in any case are composed of stars, although their dis- 
tances may be too great to enable us to prove it; 
second, nebulae properly so called, of which spectrum 
analysis demonstrates their gaseous constitution. 
Here is an instructive fact. The clusters of stars 
present the same general distribution as the telescopic 
stars — they are more numerous in the plane of the 
Milky Way, while it is the contrary which is presented 
by the nebulae properly so called ; they are rare, thinly 
spread in the Milky Way, and thickly scattered to the 
north as well as to the south of this zone up to its 
poles. The constitution of the Milky Way — not neb- 
ulous, but stellar — is a very significant fact. The 
nebulae properly so called are distributed, in a sense, 
contrary to the stars, being more numerous towards 
the poles of the Milky Way and in regions poor in 
stars, as if they had absorbed the matter of which the 
stars are formed. 



CHAPTER XXIX. 

A WHIRLING UNIVERSE. 

No REST, no quiet, no repose, in that great uni- 
verse, which to our dim eyesight looks so fixed and 
still, but one perpetual rush of moving suns and 
worlds. For every star has its own particular mo- 
tion, every sun is pressing forward in its own ap- 
pointed path. And among the myriads of stars — 
bright, blazing furnaces of white or golden, red, blue, 
or green flame — sweeping with steady rush through 
space, our sun also hastens onwards. 

The rate of his speed is not very certain, but it is 
generally believed to be about one hundred and fifty 
million miles each year. Possibly he moves in reality 
much faster. 

When I speak of the sun's movement, it must of 
course be understood that the earth and planets all 
travel with him, much as a great steamer on the sea 
might drag in his wake a number of little boats. 
From one of the little boats you could judge of the 
steamer's motion quite as well as if you were on the 
steamer itself. Astronomers can only judge of the 
sun's motion by watching the seeming backward drift 
of stars to the right and left of him ; and the watch- 
ing can be as well accomplished from earth as from 
the sun himself. 

After all, this mode of judging is, and must be, 
very uncertain. Among the millions of stars visible, 
22 337 



338 story of the; sun, moon, and stars. 

we only know the real distances of abont twenty-five ; 
and every star has its own real motion, which has to 
be separated from the apparent change of position 
caused by the sun's advance. 

It seems now pretty clear that the sun's course is 
directed towards a certain point in the constellation 
Hercules. If the sun's path were straight, he might be 
expected by and by, after long ages, to enter that con- 
stellation. But if orbits of suns, like orbits of plan- 






.•knee 




<*£ *--'" KNE£ 3 



» 

hercui.es 
ets, are ellipses, he will curve away sideways long be- 
fore he reaches Hercules. 

One German astronomer thought he had found the 
center of the sun's orbit. He believed the sun and 
the stars of the Milky Way to be traveling round the 
chief star in the Pleiades, Alcyone. This is not im- 
possible; but it is now felt that much stronger proof 
will be required before the idea can be accepted. 

In the last chapter mention was made of star- 
streams as a late discovery. Though a discovery still 
in its infancy, it is one of no small importance. Briefly 



A WHIRLING UNIVERSE. 339 

stated, the old theory as to the plan of the Milky Way 
was as follows: Our sun was a single star among mill- 
ions of stars forming the galaxy, some comparatively 
near, some lying at distances past human powers of 
calculation, and all formed upon much the same model 
as to size and brightness. Where the band of milky 
light showed, stars were believed to extend in count- 
less thousands to measureless distances. Where dark 
spaces showed, it was believed that we looked beyond 
the limits of our universe into black space. Stars scat- 
tered in other parts of the sky were supposed generally 
to be outlying members of the same great Milky Way. 
Many of the nebulae and star-clusters were believed to 
be vast and distant gatherings of stars, like the Milky 
Way itself, but separated by unutterably wide reaches 
of space. Some of these views may yet be found to 
contain truth, though at the present moment a differ- 
ent theory is afloat. 

It is still thought probable that our sun is one among 
many millions of suns, forming a vast system or col- 
lection of stars, called by some a universe. It is also 
thought possible that other such mighty collections of 
stars may exist outside and separate from our own at 
immense distances. It is thought not impossible or 
improbable that some among the nebulae may be such 
far-off galaxies of stars ; though, on the other hand, it 
is felt that every star-cluster and nebula within reach 
of man's sight may form a part of our own " uni- 
verse." 

According to this view of the question, the Milky 
Way, instead of being an enormous universe of count- 
less suns reaching to incalculable distances, may 



34-0 STORY OF THE SUN, MOON, AND STARS. 

rather be a vast and mighty star-stream, consisting of 
hundreds of brilliant leading suns, intermixed with 
thousands or even millions of lesser shining orbs. If 
this be the true view, the lesser suns would often be 
nearer than the greater suns, although more dim; 
and the Milky Way would not be itself a universe, 
though a very wonderful and beautiful portion of our 
universe. 

Which of these two different theories or opinions 
contains the most truth remains to be found out. But 
respecting the arrangement of stars into streams, in- 
teresting facts have lately been discovered. We cer- 
tainly see in the Solar System a tendency of heavenly 
bodies to travel in the same lines and in companies. 
Not to speak of Jupiter and his moons, or Saturn and 
his moons, we see it more remarkably in the hundreds 
of asteroids pursuing one path, the millions of mete- 
orites whirling in herds. Would there be anything 
startling in the same tendency appearing on a might- 
ier scale? Should we be greatly astonished to find 
streams of stars, as well as streams of planets ? 

For such, indeed, appears to be the case. Sepa- 
rated by abysses of space, brother suns are plainly to 
be seen journeying side by side through the heavens, 
towards the same goal. 

The question of star-drift is too complex and diffi- 
cult to be gone into closely in a book of this kind. 
One example, however, may be given. Almost every- 
body knows by sight the constellation of the Great 
Bear — the seven principal stars of which are called also 
Charles's Wain, a corruption of the old Gothic Karl 
Wagen, the churl's or peasant's wagon. It is also 



A WHIRLING UNIVERSE. 



341 



called the Great Dipper. Four bright stars form a 
rough sort of oblong, and from one of the corners 
three more bright stars stretch away in a curve, rep- 
resenting the Bear's tail. Many smaller stars are in- 
termixed. 

These seven bright stars have always been bound 
together in men's minds, as if they belonged to one 



*"! Front 






'• Foot- 






Nose \ 






% k 






> * x . / 












'• v \ / 


• 


• 


\ * ' *' 


Hind 




\ X 


Foot 




\ 






^ 






V'--\ 




•Hind 


Dipper \ 


< 


Foot 


Bowl \ 


.---'' 




J* — 












y 






<n '. 






1* 






*: 







» tf/ZAR 



THE GREAT BEAR. 



another. But who, through the centuries past, since 
aught was known of the real distances of the stars 
from ourselves and from one another, ever supposed 
that any among the seven were really connected to- 
gether ? 

One of these seven stars, the middle one in the 
tail, has a tiny companion-star, close to it, visible to 



342 STORY OF THE SUN, MOON, AND STARS. 

the naked eye. For a good while it was uncertain 
whether the two were a " real double," or only a seem- 
ing double. In time it became clear that the two did 
actually belong to one another. 

Mizar is the name of the chief star, and Alcor of 
the companion. Alcor is believed to be about three 
thousand times as far away from Mizar, as our earth 
from the sun. Now, if this be the width of space be- 
tween those two bright points, lying seemingly so close 
together as almost to look to the naked eye like one, 
what must be the distance between the seven leading 
stars of the Great Bear, separated by broad sky-spaces? 
Who could imagine that one of these suns had aught 
to do with the rest? 

Yet among other amazing discoveries of late years 
it has been found by means of the new instrument, 
the spectroscope, that jive out of these seven suns are 
traveling the same journey, with the same speed. Two 
of the seven appear to be moving in another direction, 
but three of the body-stars and two of the tail-stars 
are hastening in the direction away from us, all in the 
same line of march, all rushing through space at the 
rate of twenty miles each second. Some smaller stars 
close to them are also moving in the same path. Is 
not this wonderful? We see here a vast system of 
suns, all moving towards one goal, and each probably 
bearing with him his own family of worlds. 

Many such streams have been noticed, and many 
more will doubtless be found. For aught we know, 
our own sun may be one among such a company of 
brother-suns, traveling in company. 

It is difficult to give any clear idea of the immen- 



A WHIRLING UNIVERSE. 343 

sity of the universe — even of that portion of the uni- 
verse which lies within reach of our most powerful 
telescopes. How far beyond such limits it may reach, 
we lose ourselves in imagining. 

Earlier in the book we have supposed possible mod- 
els of the Solar System, bringing down the sun and 
worlds to a small size, yet keeping due proportions. 
What if we were to attempt to make a reduced model 
of the universe; that is of just so much of it as 
comes within our ken ? 

Suppose a man were to set himself to form such a 
model, including every star which has ever been seen. 
Let him have one tiny ball for the sun, and another 
tiny ball for Alpha Centauri ; and let him, as a begin- 
ning, set the two one yard apart. That single yard 
represents ninety-three millions of miles, two hundred 
and seventy-five thousand times repeated. Then let 
him arrange countless multitudes of other tiny balls, 
at due distances — some five times, ten times, twenty 
times, fifty times, as far away from the sun as Alpha 
Centauri. 

It is said that the known universe, made upon a 
model of these proportions, would be many miles in 
length and breadth. But the model would appear 
fixed as marble, yhe sizes and distances of the stars 
being so enormously reduced, their rates of motion 
would be lessened in proportion. Long intervals of 
time would need to pass before the faintest motion in 
one of the millions of tiny balls could become visible 
to a human eye. 



CHAPTER XXX. 

READING THE LIGHT. 

Several times, in the course of this book, mention 
has been made of a wonderful new instrument called 
the spectroscope. We now proceed to give a brief 
account of the origin and achievements of this newest 
of scientific appliances. The first step towards its 



THE PRISM AND SPECTRUM. 

formation was made by Sir Isaac Newton, when he 
discovered the power of the prism to decompose light. 
This consists in the fact that a ray of light, after pass- 
ing through a transparent prism, becomes expanded 
into an elongated spectrum, no longer white, but pre- 
senting an invariable succession of colors from red to 
violet. These are called the seven primary colors; 
namely, red, orange, yellow, green, blue, indigo, and 
violet. The rainbow is a familiar illustration of this 

344 



READING THE LIGHT. 



345 



spectrum with its various colors; and trie raindrops 
are the prisms which reflect and decompose the light. 
Optical science was long satisfied with this glance 
into the interior constitution of light, occupying itself 
with the phenomena of the prismatic colors, and the- 
orizing on the nature of white light. In 1802, Dr. 
W. H. Wollaston, in closely examining a spectrum, 
found it to be crossed by at least four fine dark lines. 
It is only when an extremely narrow slit is employed 




THE SPECTROSCOPE. 

in admitting the sunlight that they become visible. 
Dr. Wollaston, supposing them to be merely "natural 
boundaries" of the different color-bands, inquired no 
further; and there for a while the matter rested. Not 
many years later, in 18 15, the matter was taken up by 
a German optician and scientist of Munich, Joseph 
von Fraunhofer. Applying more delicate means of 
observation, he was surprised to find very numerous 
dark lines crossing the spectrum. 

With patience he went into the question, using the 



34 6 STORY OF THE SUN, MOON, AND STARS. 

telescope as well as a very narrow slit, and soon he 
discovered that the dark lines were to be numbered, 
not by units or by tens, but by hundreds — or, as we 
now know, by thousands B Some were in the red, some 
were in the violet, some were in the intermediate 
bands; but each one had, and has, its own invariable 
position on the solar spectrum. For, be it understood, 
these dark lines are constant, not variable. Where a 
line is seen, there it remains. Whenever a ray of sun- 
light is properly examined, with slit and with prism, 
that line will be found always occupying precisely the 
same spot in the spectrum. 

Some of the chief and more distinct lines were 
named by Fraunhofer after certain letters of the al- 
phabet, and by those letter-names they are still known. 
He began with A in the red and went on to H in the 
violet. Fraunhofer made a great many experiments 
connected with these mysterious lines, anxious to dis- 
cover, if possible, their meaning. For although he 
now saw the lines, which had scarcely so much as 
been seen before, he could not understand them — he 
could not read what they said. They spoke to him, 
indeed, about the sun ; but they spoke in a foreign 
language, the key to which he did not possess. He 
tried making use of prisms of different materials, 
thinking that perhaps the lines might be due to some- 
thing in the nature of the prism employed. But let 
the prism be what it might, he found the lines still 
there. Then he examined the light which shines from 
bright clouds, instead of capturing a ray direct from 
the sun. And he found the lines still there. For 
cloudlight is merely reflected sunlight. 



READING THE LIGHT. 



347 



Then he examined the light of the moon, to see if 
perchance the spectrum might be clear of breaks. 
And he found the lines still there. For moonlight is 
only reflected sunlight. Next he set himself to ex- 
amine the light which travels to us 
from some of the planets, imagining 
that a different result might follow. 
And he found the lines still there. 
For planet-light again is no more than 
reflected sunlight. 

Lastly, he turned his attention to 
some of the brighter stars, examining, 
one by one, the ray which came from 
each. And, behold ! he found the lines 
not there. For starlight is not re- 
flected sunlight. That is to say, the 
identical lines which distinguish sun- 
light were not there. Each star had 
a spectrum as the sun has a spectrum, 
and each star-spectrum was crossed by 
faint dark lines, more or less in num- 
ber. But the spectra of the stars dif- 
fered from the spectrum of the sun. 
Bach particular star had its own par- 
ticular spectrum of light, different 
from that of the sun, and different 
from that of every other star. For now, spectra, showing 
Fraunhofer was examining, not sun- Tm5 DARK unes. 
light, but starlight ; not the light of our sun, either 
direct from himself or reflected from some other 
body, such as planet or moon or cloud, but the light 
of other suns very far distant, each one varying 




348 STORY OF THE SUN, MOON, AND STARS. 

to some extent from the rest in its make. The 
fact of the stars showing numerous sets of black 
lines, all unlike those of our sun, showed conclu- 
sively that those lines could not possibly be due to 
anything in our earthly atmosphere. Sunlight and 
starlight travel equally through the air, and are equally 
affected by it. If our atmosphere were the cause of 
the black lines in sunlight, it would cause the same 
lines in starlight. But the sun and each individual 
star has its own individual lines, quite irrespective of 
changeful states of the air. 

So, also, the light from any metal sufficiently heated 
will give a spectrum, just as sunlight gives a spectrum, 
under the needful conditions. That is to say, there 
must be slit and prism, or slit and diffraction-grating, 
for the light to pass through. But the kind of spec- 
trum is by no means always the same. 

Putting aside for a few minutes the thought of 
sunlight and starlight, let us iook at the kind of rays 
or beams which are given forth by heated earthly 
substances. Any very much heated substance sends 
forth its light in rays or beams, and any such rays or 
beams may be passed through a prism, and broken 
up or " analyzed," just as easily as sunlight may be 
"analyzed." 

Suppose that we have a solid substance first — a 
piece of iron or of steel wire. If it is heated so far as 
to give out, not only heat, but also light, and if that 
light is made to travel through the slit and prism of a 
spectroscope, the ray will then be broken up into its 
sub-rays. They, like the sub-rays of a sunbeam, will 
form a continuous row of soft color-bands, one melt- 



READING THE LIGHT. 349 

ing into another. This is the characteristic spectrum 
of the light which is given forth by a burning or glow- 
ing solid. 

Next, suppose we take a liquid — some molten iron 
or some molten glass, for instance. If you have ever 
been to a great plate-glass manufactory, like that at 
St. Helens, not far from Manchester, you will have 
seen streams of liquid glass pouring about, carried to 
and fro in huge caldrons, bright with a living light of 
fire from its intensity of heat. If a ray of that light 
had been passed through slit and prism, what do you 
think would have been the result? A continuous 
spectrum once more, the same as with the glowing 
iron or steel. The light-ray from a heated and radiant 
liquid, when broken up by a prism, lies in soft bands 
of color, side by side. 

Both of them a good deal like the solar spectrum, 
you will say. Only here are no mysterious dark lines 
crossing the bright bands of color. But how about 
gases? Suppose we have a substance in the state of 
gas or vapor, as almost every known substance might 
be under the requisite conditions, and suppose that 
substance to be heated to a glowing brilliance. Then 
let its light be passed through the slit and prism of a 
spectroscope. What result shall we find this time? 
Entirely different from anything seen before. Instead 
of soft, continuous bands of color, there are bright 
lines, well separated and sharply denned. 

How many bright lines? Ah, that depends upon 
which particular gas is having its ray analyzed. Try 
sodium first — one of the commonest of earthly sub- 
stances. Enormous quantities of it are distributed 



350 STORY OF THE SUN, MOON, AND STARS. 

broadcast in earth and air and water. More than 
two-thirds of the snrface of onr globe lies nnder an 
enfolding vestnre of water saturated with salt, which 
is a compound of sodium. That is to say, sodium 
enters largely into the make of salt. Every breeze 
which sweeps over the ocean carries salt inland, to 
float through the atmosphere. Sir H. B. Roscoe 
writes: " There is not a speck of dust, or a mote seen 
dancing in the sunbeam, which does not contain chlo- 
ride of sodium" — otherwise salt. The very air which 
surrounds us is full of compounds of sodium, and we 
can not breathe without taking some of it into our bod- 
ies. Sodium is an " elementary substance." By which 
I mean that it is one of a number of substances called 
by us " simple," because chemists have never yet 
succeeded in breaking up those substances, by any 
means at their command, into other and different 
materials. 

Iron is, so far as we know, a simple substance. It 
is found as iron in the earth. No chemist has ever 
been able to make iron by combining other materials 
together. No chemist has ever managed to separate 
iron into other materials unlike itself. Iron it is, and 
iron it remains, whether as a solid, as a liquid, or as a 
gas. Gold is another simple substance, and so is silver. 
Sodium is another. All these we know best in the 
solid form. Mercury, another simple substance, we 
know best as a liquid. 

Water is not a simple substance ; for it can be sep- 
arated into two different gases. Glass is not a simple 
substance; for it is manufactured out of other sub- 
stances combined together. 



READING THE LIGHT. 35 1 

We can speak quite positively as to such substances 
as are not simple; but with regard to so-called " ele- 
ments," we may only venture to assert that, thus far, 
nobody has succeeded in breaking them up. There- 
fore, at least for the present, they are to us "ele- 
mentary." 

All the simple substances, and very many of the 
combinations of them, though often known to us only 
in the solid form, may, under particular conditions, be 
rendered liquid, and even gaseous. Every metal may 
be either in the solid form, or the liquid form, or the 
vapor form. Iron, as we commonly see it, is solid — 
in other words, it is frozen, like ice. Just as increase 
of warmth will turn ice into water, so a certain amount 
of heat will make solid iron become liquid iron. And 
just as yet greater warmth will turn water into steam, 
so a very much increased amount of heat will turn 
liquid iron into vapor of iron. A little heat will do 
for ice what very great heat will do for iron. 

Whether iron and other metals exist in the sun, as 
on earth, in a hard and solid form, it is impossible to 
say. It is only in the form of gas that man can be- 
come aware of their presence at that distance. The 
intense, glowing, furnace-heat of the sun causes many 
metals to be present in large quantities in the sun's 
atmosphere in the form of vapor. 

Not only have we learned about some of the metals 
in the sun, but this strange spectrum analysis has 
taught us about some of the metals and gases in the 
stars as well. It is found that in Sirius, sodium and 
magnesium, iron and hydrogen, exist. In Vega and 
Pollux there are sodium, magnesium, and iron. In 



35^ STORY OF THE SUN, MOON, AND STARS. 

Aldebaran, these substances and many others, includ- 
ing mercury, seem to abound. These are merely a few 
examples among many stars, each being in some de- 
gree different from the rest. 

But how can we know all this? How could the 
wildest guessing reveal to us the fact of iron in the 
sun, not to speak of the stars? We know it by means 
of the spectrum analysis — or, as we may say, by means 
of the spectroscope. This instrument may be looked 
upon as the twin-sister to the telescope. The tele- 
scope gathers together the scattered rays of light into 
a small spot or focus. The spectroscope tears up these 
rays of light into ribbons, sorts them, sifts them, and 
enables us to read in them hidden meanings. 

When a ray of light reaches us from the sun, that 
ray is white; but in the white ray there are bright 
colors concealed. Newton was the first to discover 
that a ray of white light is really a bundle of colored 
rays, so mixed up together as to appear white. If a 
ray of sunlight is allowed to pass through a small 
round hole in a wall, it will fall upon the opposite 
wall in a small round patch of white light. But if a 
prism — a piece of glass cut in a particular shape — is 
put in the path of the ray, it has power to do two 
curious things. First, it bends the ray out of a 
straight course, causing the light to fall upon a dif- 
ferent part of the wall. Secondly, it breaks up or 
divides the ray of white light into the several rays 
of colored light of which the white ray is really 
composed. This breaking up, or dividing, is called 
"analyzing." 

If in place of a round hole the ray of light is made 



READING THE LIGHT. 353 

to pass through a very narrow slit, it is proved that 
the bright bands of color do not overlap. Instead of 
this, dark lines, or gaps, show here and there. Now, 
these lines or gaps are always to be seen in the spec- 
trum or image of bright colors formed by a broken-up 
ray of sunlight. There is always a certain number of 
dark lines in each colored band — some near together, 
some far apart; here one or two, there a great many. 
Where a simple ray of sunlight is concerned, the exact 
arrangement of the lines never changes. 

When the stars were examined — when the rays of 
light coming from various stars were split up and 
analyzed — it was found that they too, like the sun, 
gave a spectrum of bright colors with dark lines. 
But the lines were different in number and different 
in arrangement from the sun's lines. Bach star has 
his own particular number and his own particular ar- 
rangement, and that arrangement and number do not 
change. 

If a white-hot metal is burnt, and the light of it as 
it burns is allowed to pass through a prism, a row of 
bright colors appears as in the sun's spectrum, only 
there are no dark lines. If a gas is burnt, and the 
light is allowed to pass through a prism, no bright 
color-bands appear, and no dark lines either; but in- 
stead of this, there are bright lines. Each gas or 
vapor has its own number of lines and its own ar- 
rangement. Sodium shows two bright lines, side by 
side. Iron shows sixty bright lines, arranged in a 
particular way. 

Now you see how a row of bright colors without 
bands of color may appear. But what about color- 
23 



354 STORY OF THE SUN, MOON, AND STARS. 

bands and dark lines together? That discovery came 
latest. It was fonnd that if a white-hot metal were 
burned, and if its light were allowed before touching 
the prism to shine through the flame of a burning gas, 
then there were dark lines showing in the colored 
bands. These dark lines changed in position and 
number and arrangement with each different kind 
of gas, just as the bright lines changed if the gases 
were burned alone. If the light of the burning 
metal passed through a flame colored with gas of 
sodium, two dark lines showed on one part of the 
spectrum; but if it passed through a flame colored 
with vapor of iron, sixty dark lines showed on another 
part of the spectrum. 

So now, by means of this spectrum analysis, we 
know with all but certainty that the sun and stars 
are solid, burning bodies, sending their light through 
burning, gas-laden atmospheres. By examining the 
little black lines which appear in the spectrum of one 
or another, it is possible to say the names of many 
metals existing as gas in those far-off heavenly 
bodies. Is not this a wonderful way of reading light? 

The split-up rays tell us much more than the kinds 
of metals in different stars. When a nebula is exam- 
ined, and is found to give no spectrum of bright bands 
and dark lines, but only a certain number of bright 
lines, we know it to be formed of gas, unlike stars 
and other nebulae. Also, it is by means of the spec- 
troscope that so much has lately been discovered about 
the motions and speed of the stars coming towards or 
going from us. 



CHAPTER XXXI. 

STELLAR PHOTOGRAPHY. 

Photography is not only a useful handmaid to 
astronomy as a whole, but also it is so, peculiarly, to 
that division of astronomy with which we are now 
chiefly concerned — to spectroscopy. A few pages may 
therefore with advantage be given to the subject of 
celestial photography. 

Photography is, indeed, the greatest possible help 
to the astronomer. It pictures for him those stars 
which his eyes can see but dimly, or even can not see 
at all; it paints for him those light-rays of which he 
would obtain but a passing glance, and which he 
could not accurately remember in all their details ; it 
maps out for him the wide heavens, which he, unaided, 
could never do with anything like equal completeness 
by eye and hand alone. 

Only recently a vast photographic map of the 
whole sky was undertaken. About eighteen different 
observatories, in divers parts of the world, divided the 
task among them, stars down to the sixteenth magni- 
tude being most carefully registered in a complete 
series of something like fifteen hundred separate pho- 
tographs. The whole result, when finally completed, 
will be a grand achievement of the present century. 
Each individual star, in the entire heavens all around 
our earth, from the first to the sixteenth magnitudes, 
will have its exact position in the sky accurately 

355 



356 STORY of ths sun, moon, and stars. 

known, and the smallest change in the position of any 
one of those stars may then be detected. 

Even in the delicate and abstruse operation earlier 
described, the measurement of star-distances through 
annual parallax, photography again steps in. Dr. 
Pritchard, Savilian professor of Astronomy at Oxford, 
pressed photography into the service of this task also. 
Measurements for parallax were made under his direc- 
tion upon photographic plates — a work of no small 
interest. Here, as elsewhere, peculiar advantages be- 
long to the photographic method when it can be fol- 
lowed. Its records are lasting, the limited number of 
hours which are fully suitable for direct astronomical 
work may be employed in obtaining those records, 
and in broad daylight the examination of them can be 
carried on. 

One very curious use is made of star-photographs, 
more especially of the photographs of unseen stars — 
that is, of stars too distant or too dim to be detected 
by the eye. These photographs, when taken, may 
be afterwards looked into further with a microscope. 
So, first, the far-off, invisible suns of the universe are 
photographed on a prepared plate, with the help of a 
powerful telescope, this being needful to secure suffi- 
cient starlight; and then the tiny picture of those 
suns is examined more closely with the help of a 
powerful microscope. 

Spectroscopy has much to say to us. It tells us 
about the positions of the different stars. It tells us 
about the structure of the stars. It tells us about the 
various classes to which the various stars belong. And 
also it tells us about the motions of the stars — not 



STELLAR PHOTOGRAPHY. 357 

mere apparent motions, caused by movements of our 
own earth, but true onward journeyings of the stars 
themselves through the depths of space. 

For by means of photography we do not obtain 
simple pictures of the stars themselves only, but pic- 
tures also of the spectra of the stars. An instrument 
is made uniting the spectroscope with the photographic 
apparatus, and this is called a spectrograph. By its 
means the disintegrated or broken-up star-ray is pho- 
tographed in its broken-up condition, so that an exact 
picture is obtained of the bands and lines character- 
istic of any particular star. 

No easy matter, as may be imagined, are these 
spectroscopic observations and these spectroscopic 
photographings of the stars. To bring the image of 
a star exactly opposite a slender opening or slit, per- 
haps only about the three-hundredth part of an inch 
in width, and to keep it there, is a task which might 
well be looked upon as practically impossible. 

No sooner is a star found in the field of a telescope 
than it vanishes again. As the astronomer gazes, the 
ground beneath him is ever whirling onward, leaving 
the star behind; and although clockwork apparatus 
in all observatories of any importance is made to 
counteract this motion of the earth, and to keep the 
heavenly object, whether star or moon, or comet, 
within view by following its apparent motion, yet, as 
can easily be imagined, to follow thus the seeming 
motion of a dim star through an opening so minute, 
demands exceeding care and delicacy of adjustment. 

It is not indeed, for purposes of analysis, always 
needful to pass the light of a star through a narrow 



358 STORY OF THE SUN, MOON, AND STARS. 

slit. In the case of a nearer body, snch as the sun or 
moon or one of the planets, light flows from all parts 
of the body, one ray crossing another; and for the 
examination of such light, a slit is imperatively 
needed, all side-rays having to be cut off. But the 
whole of the brightest star in the sky is only one 
point of light to us, and a slitless telescope may be 
used with no confused results. Where, however, di- 
rect comparison is required, the star-lines being made 
to appear, side by side or above and below, with the 
solar spectrum, or with the lines of earthly metals, 
then the slit becomes unavoidable. 

By such comparison of the two, side by side — the 
light from an intensely-heated earthly substance and 
the light from a star, the rays of both being broken up 
in the spectroscope — the oneness or difference of lines 
in the rays can be easily made out. 

One main difficulty in such observations arises from 
the diminution of starlight, caused by its passage 
through a prism. If a rope of a dozen strands is un- 
twisted, each of those strands is far weaker than the 
whole rope was; and each strand of color in the 
twisted rope of light is of necessity much more feeble, 
seen by itself, than the whole white ray seen in one. 
Another difficulty in our country generally is the cli- 
mate, which gives so few days or hours in the year for 
effective work. Yet the full amount accomplished by 
seizing upon every possible opportunity is, in the ag- 
gregate, astonishing. A third and very pressing diffi- 
culty attendant upon examination of star-spectra is 
caused by the incessant motion of our air, through 
which, as through a veil, all observations have to be 



STKLLAR PHOTOGRAPHY. 359 

made. The astronomer can never get away from the 
atmosphere ; and nnless the air be very still — that is 
to say, as still as it ever can remain — the spectrum- 
lines are so uncertainly seen as to make satisfactory 
results impossible. Dr. Huggins has sometimes 
passed hours in the examination of a single line, 
unable to determine whether or no it precisely coin- 
cided with the comparison-line of some earthly sub- 
stance. In this matter, no leaping at conclusions is 
admissible. 

The photography of stars would be easy enough 
if one could just expose a plate to the shining of the 
star, and there leave it to be impressed — -there leave 
the star-ray to sketch slowly its own image. But 
this is hardly possible. The unceasing motion of the 
earth, causing the star perpetually to pass away from 
the telescopic field, and the exceeding narrowness of 
the slit opposite to which the star has to be kept in a 
stationary position, make the most accurate adjust- 
ment needful. 

Clockwork alone can not be trusted. If it could, 
the star and the photographic apparatus might be 
comfortably "fixed," and left to do their own work. 
Instead of which, while a photograph is proceeding, 
it is desirable that an observer should sit gazing pa- 
tiently at the telescope-tube, where the image of the 
star is seen, ready at any moment to correct by a 
touch the slightest irregularity in the clockwork mo- 
tion of the telescope, and so to prevent a blurred 
and spoilt reproduction of the star, or of its spectrum. 

One hour, two hours, three hours, at a stretch, this 
unceasing watchfulness may have to be kept up, and 



360 STORY OF THE SUN, MOON, AND STARS. 

no small amount of enthusiasm in the cause of 
science is requisite for so monotonous and wearying 
a vigil. 

As noted earlier, it has been found possible, if the 
photograph of a star or nebula is not completed in 
one night, to renew the work and carry it on the 
next night, or even for many nights in succession. 
This is especially practicable in spectroscopic pho- 
tography. 

From four to five hours, sometimes from eight to 
ten hours, may be needful before the clear image of 
the star or of its spectrum appears — a dim little star 
probably to us, yet perhaps in reality a splendid sun, 
shedding warmth and light and life upon any number 
of such worlds as ours. 

Bight or ten hours of photography at one stretch 
with a star are impossible; for the stars, ever seem- 
ingly on the move, do not remain long enough in a 
good position. For three to six hours, a telescope 
may be made, by means of its clockwork machinery, 
to keep a star steadily in sight, and all that while 
the photograph is progressing. If further exposure 
is needed, the process has to be resumed the next 
night. 

The more one considers the matter, the more 
plainly one perceives how enormously our powers of 
sky-observation are increased by photography. It is 
not only that one photographer, with his apparatus, 
may accomplish in a single night the work of many 
astronomers who have to depend upon the power of 
the eye alone. It is not only that, with the help of 
photography, as much can now be done in a lifetime 



STELLAR PHOTOGRAPHY. 36 1 

as formerly must have occupied many generations. It 
is not only that the photograph, once taken, remains a 
permanent possession, instead of a record, more or less 
imperfect, in which otherwise the astronomer would 
have to trust. 

It is not even only that in the photograph details 
come out which could not be detected by the eye, and 
that stars are actually brought to our knowledge which 
no man has ever seen, which perhaps no man ever will 
see from this earth with the assistance of the most 
powerful telescope. For the weak shining, which can 
by no possibility make itself felt by the retina of a 
man's eye, can slowly impress its picture on the pho- 
tographic plate. Hundreds of stars, thousands of 
stars, utterly invisible to man, have had their photo- 
graphs taken as truly as you have had your photo- 
graph taken, and by the same process, only it has 
been a longer business. 

But in addition to all this, we see reproduced upon 
the plate those ultra-violet and infra-red portions of 
the spectrum of light which but for the handmaid, 
photography, would still be to us as things which 
have no existence. And by means of photography 
we can observe and study in those same unseen por- 
tions of the spectra, when looking into a ray from sun 
or star, the innumerable dark lines, every one of which 
has its own tale to tell. To these tales we must have 
remained blind and deaf, but for photographic aid to 
our limited powers. 

Iyook at some dim star in the sky, and try how long 
you can gaze without blinking. You will very soon 
find that you have done your best, and that to gaze 



362 STORY OF THE SUN, MOON, AND STARS. 

longer only means a sense of fatigue in yonr eyes, a 
growing dimness in the star. How different with the 
photographic plate ! There, no exertion is wasted, no 
weariness is felt. Faint thongh the light may be, 
which travels earthward and falls upon the plate, it is 
all collected, all used. 

It is easy to photograph the sun, and this has been 
done. When we come to the moon the operation is 
more difficult on account of the feeble intensity of its 
light, and the difference of tint of the various parts 
of its surface. Skill and perseverance have, however, 
surmounted the greatest difficulties, and now we have 
photographs of the moon enlarged to more than a 
yard in diameter, which show the smallest details 
with a truly admirable clearness. 

In the first second of time, your eye receives as 
much light from the star as does the photographic 
plate in the same time. But during the course of 
one hour, the plate receives and stores up about thirty- 
six hundred times as much light as it or you received 
in the first instant. There is the secret of the matter. 
The photographic plate does not only receive, it can 
also keep and treasure up the light, and that our eyes 
are not able to do. 

If you magnify the amount received in one hour 
by five or ten, and remember that it is all retained, 
then you will begin to understand how feeble stars, 
unseen by man, should become known to us through 
photography. 



CHAPTER XXXII. 

THE DAWN OF ASTRONOMY. 

The beginnings of astronomy lie in the distance of 
earliest historical ages. It is no easy matter to say 
when first, in all probability, this science grew into 
existence. Astronomy was alive before the British 
nation was heard of; before Saxons or Franks had 
sprung into being ; before the Roman Empire extended 
its iron rule; before the Grecian Empire began to 
flourish ; before the Persian Empire gained power; be- 
fore the yet earlier Assyrian Empire held sway. 

Among the ancient Chaldeans were devoted star- 
gazers — much more devoted than the ordinary run of 
educated Anglo-Saxons in this present century. They 
earnestly sought, in the dim light of those ages, to 
decipher the meaning of heaven's countless lamps. 
We have better instruments, and more practiced modes 
of reasoning; also, we have the collected piles of knowl- 
edge built up by our forefathers through tens of cen- 
turies. Yet our search is in essence the same as was 
theirs, to know the truth about the stars: not merely 
to start some attractive theory, and then to prove that 
our theory must be right, because we have been so 
clever as to start it ; but to discover that which is in 
those regions of space. No lower aim than this is 
worthy to be called scientific. 

Mistakes, of course, are made; how should it be 
otherwise ? A man finding his way at night, for the 

3 6 3 



364 STORY OP TH£ SUN, MOON, AND STARS. 

first time, through a wild and unknown country, will 
almost certainly take some wrong turns before he dis- 
covers the right road. In astronomy, as in all other 
natural sciences, blunders are a necessity if advance is 
to be made. We have to grope our way to knowl- 
edge through observation and conjecture ; in simpler 
terms, through gazing and guessing. Observation of 
facts leads to conjecture as to the possible causes for 
those facts; and each conjecture is proved by later ob- 
servation to be either right or wrong. If proved to be 
right, it takes its place among accepted truths; if proved 
to be wrong, it is flung aside. Some pet delusions 
die hard, because of people's love for them. 

Astronomy, as an infant science, mixed up with as- 
trology, existed in the days when the Pyramids were 
juvenile, and when the Assyrian sculptures were mod- 
ern. How much farther back who shall say? By 
astrology, those who studied the heavens endeavored 
to determine the fate of men and of nations, to pre- 
dict events, and to interpret results. They paid par- 
ticular attention to the aspect of the planets, and the 
general appearance of the firmament. 

These observations were at first simple remarks 
made by the shepherds of the Himalayas after sunset 
and before sunrise : The phases of the moon, and di- 
urnal retrograde motion of that body with reference to 
the sun and stars ; the apparent motion of the starry 
sky accomplished silently above our heads ; the move- 
ments of the beautiful planets through the constella- 
tions ; the shooting star, which seems to fall from the 
heavens; eclipses of the sun and moon, mysterious 
subjects of terror ; curious comets, which appear with 



THE DAWN OF ASTRONOMY. 365 

disheveled hair in the heights of heaven, — such were 
the first subjects of these old observations made during 
thousands of years. 

The ancient Chaldean star-gazers had rivals among 
the early Egyptians ; and the Chinese profess to have 
kept actual record of eclipses during between three 
and four thousand years. The earlier records are not 
trustworthy; but of thirty-six eclipses reckoned by 
the Chinese sage, Confucius, no less than thirty-one 
have been proved true by modern astronomers. 

We can not name with certainty those people whose 
shepherds first gazed with intelligent eyes upon the 
midnight sky, and noted the steady sweep of stars 
across the firmament — intelligent eyes, that is to say, 
so far as man then knew how to use his eyes intelli- 
gently; so far as man had begun to note anything in 
nature, to watch, to compare, and to conjecture causes. 

In those times, and indeed for long afterwards, men 
thought much more about the " influences" of stars 
upon their own lives, and about supposed prophecies 
of the future to be read in the sky, than about the 
actual physical condition of the stars themselves, or 
the causes and meanings of the various phenomena 
observed in the heavens. 

The desire to know, for the pure delight of know- 
ing, had perhaps hardly begun to dawn upon the mind 
of man. What people did want to know was what 
might be going to happen to themselves ; whether they 
would be happy or unhappy ; and the stars were chiefly 
of interest as appearing to tell beforehand of troubles 
or joys to come. 

The wisest of men in those times knew less of the 



366 STORY OF THE SUN, MOON, AND STARS. 

outspread heavens than many a child now knows in 
our public schools. Earth and sky were one vast be- 
wildering puzzle. They had to discover everything 
for themselves — how the sun rose each morning and 
set each evening; how the seasons changed in steady 
sequence through the year; how the moon and stars 
journeyed in the night ; how the ocean-tides went and 
came; how numberless every-day phenomena took 
place. 

In olden days the daily rising and setting of the 
sun was a mystery, accounted for by divers theories, 
none of which were right; and the march of stars 
across the midnight sky was a complete puzzle ; and 
an eclipse of sun or moon was a fearful perplexity ; 
and the tides of ocean were a great bewilderment. 
These things are mysteries still to barbarbous nations ; 
but they perplex us no longer, because we have found 
out the mode in which such movements, or appear- 
ances of movement, are brought about through the ac- 
tion of quite natural causes. 

As a first step, in earliest times, the journey of the 
sun by day, the journeys of moon and stars by night, 
across the sky, could hardly fail to arrest attention. 
Very early, too, the stars were grouped into constella- 
tions, definite figures and names being attached to 
each. Many of the constellations are now known to 
us by names which belong to the earliest historic ages. 

The stars were known as " fixed," because they 
continued unchangeably in their relative positions — 
that is, in the position held by each star with respect 
to its neighbor stars — although the whole array of 
them moved nightly in company ; constellations rising 



THE DAWN OF ASTRONOMY. 367 

and setting at night, as the sun rose and set in the 
day. 

Ages may well have passed before the planets were 
recognized as distinct from the fixed stars ; ages more 
before any definite plan was noted in their wander- 
ings. In the course of time men's attention was di- 
rected to these matters ; and one fact after another, of 
daily or monthly or yearly occurrence, was observed, 
and commented upon, and became familiar to the 
minds of people. Very slowly the first beginnings of 
systematized knowledge took shape and grew, one 
discovery being made after another, one explanation 
being offered after another, one theory being started 
after another. 

But an essential difference existed between the in- 
fantine science of those primitive days and the matured 
astronomy of these later days. The whole ancient 
science was built upon a huge mistake. Men held, as 
a fact of absolutely unquestionable certainty, that this 
earth of ours — this small whirling globe, less than eight 
thousand miles in diameter — was the center, around 
which sun, moon, and stars all revolved. 

The Greek philosopher Thales, who lived about six 
hundred years before Christ, is said to have laid the 
foundations of the Grecian astronomy; and Pythag- 
agoras is stated to have been one of his disciples. 
Though, in many respects, Thales wandered wide of 
the truth, he yet taught many correct ideas ; as, for in- 
stance, that the stars were made of fire ; that the moon 
had all her light from the sun ; that the earth was a 
-sphere in shape, besides other facts respecting the 
earth's zones and the sun's apparent path in the sky. 



368 STORY OF THK SUN, MOON, AND STARS. 

He was also one of the three ancient astronomers who 
were able to calculate and foretell eclipses. 

After him came numerous astronomers, of greater 
or less merit, in the Grecian and in other schools. 
They watched carefully; they discovered many things 
of interest; they held divers theories. But one truth 
never took firm root among them, although several of 
them dimly apprehended it; and this was the very 
foundation-truth, for lack of which they were all go- 
ing hopelessly astray — the simple truth that our earth 
is not the center of the universe, and that our earth 
does move. Yet it is not surprising. No wonder they 
were slow to grasp such a possibility. 

Anything more bewildering to the mind of ancient 
man than the thought of a solid, substantial world 
floating in empty space, supported upon nothing, up- 
held by nothing, can hardly be imagined. As yet 
little was known of the controlling laws or forces of 
nature, and that little was with reference only to our 
earth. The very suspicion of gravitation as a uni- 
versal law lay in the far-distant future, waiting for the 
intellect of a Newton to call it out of apparent chaos ; 
and the delicate balance of forces, by means of which 
the Solar System may almost be said to exist, could 
not be so much as guessed at. 

So men still clung to the thought of earth as the 
center of all things, and still believed in a little sun, 
busily circling round her once in every twenty^four 
hours. 

Perhaps the greatest of all ancient astronomers was 
Hipparchus, about 150 B. C, who did more than any 
other in those early times to gather together the scat- 



the; dawn ok astronomy. 369 

tered facts of astronomy, and to arrange them into 
one united and orderly whole. He it was who discov- 
ered the precession of the equinoxes. He studied 
eclipses and the motions of the various planets. He 
made elaborate and valuable astronomical tables and 
star-catalogues; but he, like others, failed to discover 
the gigantic error which lay at the root of the whole 
ancient science. 

Despite this great mistake, still persistently be- 
lieved in, and despite the crude notions of early as- 
tronomers on many points, it is marvelous how much 
they did manage to observe and to learn for them- 
selves, — as to the sun and his apparent path, as to 
the moon and her path, as to the five then known 
planets and their paths, as to eclipses and other phe- 
nomena. 

By all such careful watching, although they to some 
extent missed their aim and fell into mistakes, yet they 
paved a way to later discoveries and to fuller knowl- 
edge. Their work was not thrown away, their trouble 
was not lost; for out of their very errors grew the fair 
form of truth. 

Nearly three hundred years after the time of Hip- 
parchus came the famous Ptolemy — famous, not, like 
certain other astronomers, lor stupendous genius, or 
for the brilliancy and accuracy of his observations, 
but rather noted for the ingenuity of his explanations, 
and for the adroit manner in which he systematized 
such knowledge, on the subject of the heavenly bodies, 
as was then in the possession of mankind. 

Ptolemy's name is best known in connection with 
what is commonly called "The Ptolemaic System of 
24 



370 STORY OF The sun, moon, and stars. 

the Universe, " and his greatest astronomical work is 
best known as the Almagest. 

A great many of Ptolemy's leading notions, as well 
as the principal mass of facts upon which he worked, 
were doubtless borrowed from Hipparchus. The latter 
is said to have explained the movements of the sun 
and of the moon by means of small epicycles, travel- 
ing round the earth on circular orbits ; and even Hip- 
parchus did not originate this fundamental idea of the 
so-called " Ptolemaic System," which had indeed been 
held by the ancients in much earlier days. Hippar- 
chus worked it out to some extent, and Ptolemy car- 
ried on the process much farther, giving forth the 
system to the world in such wise that ever since it has 
gone by his name. 

The theory of cycles and epicycles lasted long — 
lasted from the time of Ptolemy in the second century 
to the time of Copernicus in the sixteenth century, of 
whom we have already spoken. 

[For about two thousand years, astronomers ob- 
served attentively the apparent revolutions of the 
heavenly bodies, and this attentive study gradually 
showed them a large number of irregularities and in- 
explicable complications, until at last they recognized 
that they were deceived as to the earth's position, in 
the same way that they had been deceived as to its sta- 
bility. The immortal Copernicus, in particular, dis- 
cussed with perseverance the earth's motion, already 
previously suspected for two thousand years, but al- 
ways rejected by man's self-love ; and when this learned 
Polish canon bid adieu to our world in the year 1543, 
he bequeathed to science his great work, which dem- 



THE DAWN OF ASTRONOMY. 37 1 

onstrated clearly the long-standing error of man- 
kind.—^.] 

The new theory of Copernicus had to make its 
way slowly against the dead weight of unreasoning 
public opinion, and against wrongly-reasoning hier- 
archical opposition. In time, gradually, despite all 
resistance, the truth made its way, and was generally 
received, though not till Galileo had been forced by 
ecclesiastical authority to recant his opinions. All 
the same, Copernicus, Kepler, Galileo, were right; 
public sentiment and the Church were wrong, — the 
earth did move, and was not the fixed universe cen- 
ter, and, by and by, those who lived on earth had to 
acknowledge the same. 

The succession of these great men is interesting to 
note. Between the two shining lights, Hipparchus 
and Ptolemy, nearly three hundred years intervened. 
But as the history of the world advances, we find 
brilliant scientific minds appearing more quickly, one 
following close upon another, instead of their being 
divided by long intervals of blankness. 

Within thirty years from the death of Copernicus, 
were born two mighty men of Science: Kepler, who 
lived till 1630; and Galileo, who lived till 1642, when 
England was plunged in civil strife. 

Between Copernicus and Kepler came Tycho Brahe. 
Copernicus was a Roman ecclesiastic, born in Poland. 
Tycho Brahe was a wealthy Danish nobleman, an ar- 
dent lover of astronomy, and a most patient and ac- 
curate observer. But Tycho held fast by the old 
astronomy. He was not convinced by the arguments 
of Copernicus. To him, earth was still the motion- 



372 STORY OF THE SUN, MOON, AND STARS. 

less center of all things. He was willing to allow 
that the rest of the planets circled round the sun, as 
an explanation of things which he could not help see- 
ing; but the sun itself had still, in Tycho's imagina- 
tion, to revolve daily, with planets and stars and the 
whole sky, round our earth. 

As an explainer of causes, therefore, Tycho rose to 
no lofty heights. The real good which he did was in 
watching and noting actual phenomena, not in trying 
to explain how those phenomena were brought about. 
This was left for one of his young pupils, a sickly Ger- 
man lad, named John Kepler. 

In later years, Kepler made a grand use of his 
master's mass of careful and thoroughly dependable 
observations. These had really been gathered to- 
gether by Tycho, with a view of disproving the 
Copernican theory, and of establishing the main fea- 
tures of the olden astronomy, with certain improve- 
ments. But Kepler used the accumulated informa- 
tion to disprove the old astronomy, and to establish 
the truth of the new Copernican system which Tycho 
had rejected. He found a vast advantage, ready to 
his hand, in the collection of careful observations sys- 
tematically worked out by Tycho in his observatory 
during many a long year. And Kepler did not fail to 
use his advantage. 

The planets still refused, as they always had re- 
fused, to keep to the paths marked out for them by 
astronomers. Kepler grappled with the difficulty. 
He particularly turned his attention to Mars, that 
near neighbor of ours, in which we are all now so 
much interested. A long series of close observations 



The dawn of astronomy. 373 

of Mars's movements, made by Tycho in the course 
of many years, lay before him; and he knew that he 
could depend upon the absolute honesty and accuracy 
of Tycho's work. 

With immense labor and immense patience, he 
went into the matter, still clinging to the old idea of 
a circular pathway round the sun. He tried things 
this way and that way. He placed his orbit in imag- 
ination after one mode and another mode; he con- 
jectured various arrangements ; he tested and proved 
them in turn, comparing each plan with observations 
made, — and still Mars defied all his efforts ; still the 
little world went persistently wrong, traveling con- 
trary to every theory. 

Thus far, nobody had ever thought of an orbit of 
any other shape than a circle. When a straightfor- 
ward journey round a circle was found impossible, 
then epicycles were introduced to explain the planet's 
perplexing motions. No one had dreamt of an elliptic 
pathway. But suddenly a gleam of daylight came 
upon this groping in the dark. What if Mars trav- 
eled round the sun — not in a circle, but in an oval? 

Kepler tried this oval and that oval, comparing ob- 
servations past — testing, examining, proving or dis- 
proving, with unwearied patience. And at length he 
found, beyond dispute, that Mars actually did travel 
round the sun in a yearly pathway, which was shaped, 
not as a circle, but as the kind of oval known as an 
ellipse; and, further, that the sun was not in the exact 
center of this ellipse, but to one side of the center, in 
one of the foci. Kepler's success in detecting the true 
shape of a planetary orbit is doubtless owing to the fact 



374 STORY OF THK SUN, MOON, AND STARS. 

that the orbit of Mars makes a wider departure from the 
circular form than any of the other important planets. 

One step further would have led Kepler to the 
knowledge that comets also travel in elliptic orbits — 
only in very long and narrow ones generally. But he 
had quite made up his mind that all comets merely 
paid our sun one visit, and never by any chance re- 
turned; so he did not trouble himself to enter into 
calculations with respect to them. This taking for 
granted of ideas long held was a very common prac- 
tice in those days. 

The above wonderful discovery of elliptic orbits, in 
place of circular orbits, was only one among many 
made by the illustrious Kepler — discoveries not care- 
lessly hit upon, as one might pick up in the street a 
valuable stone which somebody had dropped, but ear- 
nestly sought for, and found with toil and diligence, 
as gems are first found in foreign lands, after much 
seeking and long patience. Casual discoveries in 
science are rare. Attainment is far more usually 
made through intense study, through hard work, 
through profound thought, through a gradual groping 
upward out of darkness to the point where daylight 
breaks forth. 

The three well-known "L,aws of Kepler" still lie 
at the very foundation of the modern system of as- 
tronomy. They are : First, every planet moves in an 
elliptical orbit, in one focus of which the sun is sit- 
uated; second, the line drawn from the sun to a 
planet moves over equal areas in equal times; and, 
third, the square of the periodic times of the planets 
varies inversely as the cubes of their distances. 



CHAPTER XXXIII. 

MODERN ASTRONOMY. 

Still, however, the world was not convinced of 
the truth of the Copernican system. One man here 
or there saw and acknowledged its reality. The mass 
of mankind continued firmly to believe that they 
dwelt at the universe center, and utterly to scout the 
idea of a moving earth. Indeed, it may be very much 
doubted whether, not merely the mass of mankind, 
but even the most civilized and cultivated portion of 
that mass, had as yet, to any wide extent, heard a 
whisper of the new theories. Knowledge, in those 
days, traveled from place to place with exceeding de- 
liberation. 

Another great man arose, contemporary with Kep- 
ler — a man whose story seizes more strongly upon our 
imagination than that of the severe and successful 
studies of Kepler. From an ordinary worldly point of 
view, Kepler would hardly be looked upon as altogether 
a successful man. He was poor, and in sickly health. 
His chief book was promptly prohibited by Rome — 
then a power in the whole reading world of Europe to 
an extent which can hardly be realized in these days 
of freedom. Kepler's book was placed in the forbid- 
den category, side by side with the dying publication 
of Copernicus. This checked all hope of literary 
gains, and life with Kepler was one long struggle. 
But if he could have looked ahead two or three hun- 

375 



376 

dred years ; if he could have foreseen the time when 
not a few wise men of science alone, but all the civilized 
world, including the very Church which condemned 
him, should meekly have accepted and indorsed his 
discoveries, — then he would have been able to gauge 
the measure of his own real success. 

Moreover, with all his troubles, Kepler was so 
happy as to escape absolute persecution. He lived in 
a country which knew something of liberty as an ideal; 
he was left to write and work freely ; and, at least, no 
public recantation of what he held to be truth was 
forced from him. 

Galileo's was a sadder tale. A Florentine of noble 
birth, he turned his attention early to science as the 
needle turns to the north, and before the age of twenty- 
seven he already occupied a foremost position as math- 
ematical lecturer at Pisa. There it was that he dire- 
fully offended the philosophers of the day by proving 
Aristotle to be in the wrong. For Aristotle was the 
great master of the schoolmen. His philosophy and 
theories were accepted as final, and whatsoever could 
not be proved in accordance with them was regarded 
as untrue. Aristotle had declared that if two weights 
— the one being ten times as heavy as the other — were 
dropped together from a height, the heavier weight 
would reach the ground ten times as quickly as the 
lighter. 

Everybody believed this, and nobody had ever 
thought of putting it to the test of actual trial. Aris- 
totle had said so, and Aristotle was indorsed as a whole 
by all the schools of Europe; and what more could 
possibly be wanted by any reasonable human being? 




j%uj Jiuller. , 

Prominent Astronomers of the Nineteenth Century. 

377 



378 STORY OF run SUN, MOON, AND STARS. 

But Galileo was not so easily satisfied. He looked 
into the matter independently, bent upon finding out, 
not what Aristotle had thought or what the Church 
might support, but simply what actually was. 

Then, in view of many observers, called together 
for the occasion, he dropped, at the same instant, from 
the top of the leaning tower of Pisa, a shot weighing 
one pound and another shot weighing a hundred 
pounds. And, behold ! both reached the ground si- 
multaneously. There was not a fraction of difference 
between the two. To prove Aristotle wrong was to 
prove everybody wrong, the authorities of the Church 
included. Men calmly declined to believe their own 
eyes, and Galileo was in very evil odor. 

From falling bodies he went on to subjects of yet 
wider interest to people in general. He read about 
and eagerly embraced the Copernican system. Not 
only did he accept it himself, but he vigorously set to 
work to teach and convince others also. This, as 
might only be expected, aroused vehement opposition. 
But Galileo was still in the heyday of his powers, and 
he was not to be easily silenced. In those days he 
could afford to press onward in the teeth of resistance, 
and to laugh at men who would not listen. 

When at Venice, a report reached him of a certain 
optician in Holland who had happened to hit upon a 
curious " combination of lenses," through which ob- 
jects afar off could be actually seen as if they were 
near. Galileo promptly seized upon the notion, and 
within twenty-four hours he had rigged up a small, 
rough telescope out of an old organ-pipe and two 
spectacle-glasses. 



MODERN ASTRONOMY. 379 

Thus the first telescope was made — a very ele- 
mentary affair, formed of two lenses, convex and con- 
cave, and capable of magnifying some three times — a 
mere child's toy compared with telescopes of the 
present day, but of exceeding value and interest, be- 
cause it was the very first; because in all the history 
of the world no telescope had ever been manufactured 
before. 

This earliest effort was speedily improved upon. 
The next trial produced a tube which could magnify 
seven or eight times; and in a little while, Galileo 
had a telescope magnifying as much as thirty-two 
times. Even thirty-two times does not sound very 
startling to us; but in those days the revelations of 
such an instrument came upon men like a thun- 
derclap. 

Through it could be seen clearly the broken nature 
of the moon's surface — the craters, the shadows, the 
mountains. Through it could be seen the phases of 
Venus, which no man had ever yet detected, but 
which Copernicus had declared must certainly exist, 
if indeed his system were a reality. Through it could 
be seen four of the moons of Jupiter, and their ceaseless 
journeyings. Through it could be seen spots upon 
the face of the sun, the movements of which showed 
the rotation of the sun upon his axis. Through it 
could be seen the very curious shape of Saturn, 
caused by his rings, though a much stronger power 
was needed to separate the rings from the body of the 
planet. 

Of all these discoveries, and many others also made 
by Galileo, none seemed worse to the bigoted school- 



380 STORY OP THE SUN, MOON, AND STARS. 

men of his day than the preposterous notion of black 
spots upon the sun's face. 

Rather curiously, no human being seems ever be- 
fore then to have noticed such spots, though often they 
are quite large enough to be detected by the naked 
eye. A general belief had been held that the sun was 
and must be perfect — an absolutely spotless and un- 
blemished being, the purest symbol of celestial in- 
corruptibility — and the said discovery went right 
in the teeth of deductions drawn from, and lessons 
founded upon, this belief. Therefore the schoolmen 
held out and determinedly resisted, and would have 
nought to do with Galileo or his telescopes, shutting 
their eyes to marvels newly revealed. 

But Kepler was a true scientist, a man who earnestly 
pursued truth, and sought to discover it at any hazard. 
He and Galileo were contemporaries, and they held 
communication on these subjects. Some of Galileo's 
discoveries went quite as much in the teeth of some 
of Kepler's most dearly-loved theories as they did in 
the teeth of the schoolmen's most dearly-loved doc- 
trines. Yet, none the less, Kepler welcomed them 
with great delight and eagerness, showing thereby his 
true greatness of character. 

Till after the age of fifty, Galileo was allowed to go 
on undisturbed, or at least not materially disturbed, 
by opposition in his career of success — observing, 
learning, theorizing, calculating, explaining, teaching 
— a prominent figure indeed. Not only did he take a 
large share in establishing firmly the Copernican sys- 
tem of astronomy, but some of the principal laws of 
motion were discovered by him. He first found the 



MODERN ASTRONOMY. 38 1 

uses of a pendulum, and there is strong reason for be- 
lieving that the first microscope, as well as the first 
telescope, was from his hands. 

But after the age of fifty, reverses came, and one 
blow succeeded another. Rome had been gradually 
waking up to the true sense of all that was implied 
by his discoveries and his teaching, and at length she 
let loose her thunders — impotent thunders enough, so 
far as regarded any permanent checking of the prog- 
ress of truth, but by no means impotent to crush one 
defenseless victim, the champion of scientific truth in 
that country and age. 

Years of greater or less opposition, amounting often 
to persecution, were followed by an imperious order 
commanding him to Rome. There he was examined 
and severely " questioned," and recantation was forced 
from him, worth as much as such forced recantations 
commonly are worth. 

Even then he did not cease from the work that he 
loved; even in prison he carried it on; even when he 
might not write, nothing could stop him from think- 
ing. But his health was broken ; his liberty was taken 
away; illness followed illness; his favorite daughter 
died; his eyesight gradually failed; the last book that 
he wrote might not for a long while be printed; and 
at last he passed away, mercifully set free from those 
who, in an essentially bigoted and intolerant age, were 
incapable of appreciating his greatness. 

They would fain then have denied him even a re- 
spectable grave. Now, all the civilized world unites 
to honor the name of Galileo. 



CHAPTER XXXIII. 

ISAAC NEWTON. 

Even the great fame of Galileo must be relegated 
to a second place in comparison with that of the phi- 
losopher who first saw the light in a Lincolnshire 
farmhouse on the 25th of December, 1642, the very 
same year of Galileo's death. His father, Isaac New- 
ton, had died before his birth. The little Isaac was 
at first so frail and weakly that his life was despaired 
of. The watchful mother, however, tended her deli- 
cate child with such success that he ultimately ac- 
quired a frame strong enough to outlast the ordinary 
span of human life. 

In due time the boy was sent to the public school 
at Grantham. That he might be near his work, he 
was boarded at the house of Mr. Clark, an apothecary. 
He had at first a very low place in the class. His first 
incentive to diligent study seems to have been derived 
from the circumstance that he was severely kicked by 
one of the boys above him in the class. This indig- 
nity had the effect of stimulating young Newton's ac- 
tivity to such an extent that he not only attained the 
desired object of passing over the head of the boy 
who had maltreated him, but continued to rise until 
he became the head of the school. 

The play-hours of the great philosopher were de- 
voted to pursuits very different from those of most 
schoolboys. His chief amusement was found in mak- 

382 



ISAAC NEWTON. 3S3 

ing mechanical toys, and various ingenious contriv- 
ances. He watched, day by day, with great interest, 
the workmen engaged in constructing a windmill in 
the neighborhood of the school, the result/, of which 
was that the boy made a working model of the wind- 
mill and of its machinery, which seems to have been 
much admired as indicating his aptitude for mechan- 
ics. We are told that he also indulged in somewhat 
higher nights of mechanical enterprise. The first 
philosophical instrument he made was a clock, which 
was actuated by water. He also devoted much atten- 
tion to the construction of paper kites, and his skill in 
this respect was highly appreciated by his school- 
fellows. Like a true philosopher, even at this stage, 
he experimented on the best methods of attaching the 
string, and on the proportions which the tail ought 
to have. 

When the schoolboy at Grantham was fourteen 
years of age, it was thought necessary to recall him 
from the school. His recently-born industry had been 
such that he had already made good progress in his 
studies, and his mother hoped that he would now lay 
aside his books, and those silent meditations to which, 
even at this early age, he had become addicted. It 
was hoped that instead of such pursuits, which were 
deemed quite useless, the boy would enter busily into 
the duties of the farm and the details of a country 
life. But before long it became manifest that the 
study of nature and the pursuit of knowledge had 
such a fascination for the youth that he could give 
little attention to aught else. It was plain that he 
would make but an indifferent farmer. He greatly 



384 STORY OF THE SUN, MOON, AND STARS. 

preferred experimenting on water-wheels, and working 
at mathematics in the shadow of a hedge. 

Fortunately for humanity, his mother, like a wise 
woman, determined to let her boy's genius have the 
scope which it required. He was accordingly sent 
back to Grantham school, with the object of being 
trained in the knowledge which would fit him for en- 
tering the University of Cambridge. 

It was the 5th of June, 1660, when Isaac Newton, 
a youth of eighteen, was enrolled as an undergraduate 
of Trinity College, Cambridge. Little did those who 
sent him there dream that this boy was destined to be 
the most illustrious student who ever entered the por- 
tals of that great seat of learning. Little could the 
youth himself have foreseen that the rooms near the 
gateway which he occupied would acquire a celebrity 
from the fact that he dwelt in them, or that the ante- 
chapel of his college was in good time to be adorned 
by that noble statue of himself which is regarded as 
the chief art treasure of Cambridge University, both 
on account of its intrinsic beauty and the fact that it 
commemorates the fame of her most distinguished 
alumnus, Isaac Newton, the immortal astronomer. His 
advent at the university seemed to have been by no 
means auspicious or brilliant. His birth was, as we have 
seen, comparatively obscure, and though he had already 
given indication of his capacity for reflecting on philo- 
sophical matters, yet he seems to have been but ill- 
equipped with the routine knowledge which youths are 
generally expected to take with them to the universities. 

From the outset of his college career, Newton's at- 
tention seems to have been mainly directed to mathe- 



ISAAC NEWTON. 385 

matics. Here he began to give evidence of that mar- 
velous insight into the deep secrets of nature which, 
more than a century later, led so dispassionate a judge 
as Laplace to pronounce Newton's immortal work as 
pre-eminent above all the productions of the human 
intellect. But though Newton was one of the very 
greatest mathematicians that ever lived, he was never 
a mathematician for the mere sake of mathematics. 
He employed his mathematics as an instrument for 
discovering the laws of nature. 

His industry and genius soon brought him under 
the notice of the university authorities. It is stated 
in the university records that he obtained a scholar- 
ship in 1664. Two years later we find that Newton, 
as well as many residents in the university, had to 
leave Cambridge temporarily on account of the break- 
ing out of the plague. The philosopher retired for a 
season to his old home at Woolsthorpe, and there he 
remained until he was appointed a Fellow of Trinity 
College, Cambridge, in 1667. From this time on- 
wards, Newton's reputation as a mathematician and 
as a natural philosopher steadily advanced, so that in 
1669, while still but twenty-seven years of age, he 
was appointed to the distinguished position of pro- 
fessor of Mathematics at Cambridge. Here he found 
the opportunity to continue and develop that marvel- 
ous career of discovery which formed his life's work. 

The earliest of Newton's great achievements in 
natural philosophy was his detection of the composite 
character of light. That a beam of ordinary sun- 
light is, in fact, a mixture of a very great number of 
different colored lights, is a doctrine now familiar to 
25 



386 STORY OF THE SUN, MOON, AND STARS. 

every one who has the slightest education in physical 
science. We must, however, remember that this dis- 
covery was really a tremendous advance in knowledge 
at the time when Newton announced it. 

A certain story is often told about Newton. It is 




SIR ISAAC NEWTON. 

said that as he sat in a garden an apple fell from a 
tree, and that its fall set him thinking, and that, in 
consequence of this train of thought, he found out all 
about the law of attraction or gravitation. 

But the fall of an apple .could not possibly have set 
Newton thinking, because he had already been think- 



ISAAC NEWTON. 387 

ing long and hard upon these difficult questions. In- 
deed, it was because he had been so thinking, because 
his mind was in a watchful and receptive condition, 
that so slight a matter as a falling apple should, per- 
haps, have suggested to him a useful train of ideas. 

Newton was a man who really did think, and who 
really did think intensely. He was not, like the or- 
dinary run of people, one who merely had a good 
many notions walking loosely through his brain. He 
would bend his mind to a subject and be absolutely 
absorbed in it ; later in life so absorbed that he would 
forget to finish his dressing, and would be unable to 
say whether or no he had dined. This sort of forget- 
fulness does sometimes spring from vacancy of mind; 
but with Newton it arose from fullness of thought. 

An apple falls, of course, as a stone or any other 
body falls, because the earth attracts it. Otherwise, 
it might as easily rise and float away into the sky. 
But this was known perfectly well long before New- 
ton's days. It was clearly understood that the earth 
had a curious power of drawing all things towards 
herself. People could not explain why or how it was 
so ; neither can we explain now ; but they were fully 
aware of the fact. 

So men knew something of the force called grav- 
ity ; but they knew it mainly, almost exclusively, as 
having to do with our earth, and with the things upon 
our earth. They had not begun definitely to think of 
gravity as having to do with bodies in the heavens; 
as being a chief controlling force in the whole Solar 
System; much less as reigning throughout the vast 
universe of stars. It had not come into their minds 



388 STORY OF THE SUN, MOON, AND STARS. 

with any distinctness that, just as the earth pulls to- 
wards her own center a mountain, a horse, a man, so 
the sun pulls toward his center the earth, the moon, 
and all the planets. 

Certain glimmerings of the notion had, indeed, 
begun to dawn on the horizon of learning. Horrocks, 
Borelli, Robert Hook, Wren, Halley, and others had 
glimpses of univeral gravitation; but only glimpses. 
A gifted English philospher, late in the sixteenth cen- 
tury, Gilbert by name, went so far as to speak of earth 
and moon acting one upon the other " like two mag- 
nets." He also saw the effect of the moon's attraction 
in bringing about ocean tides, though he oddly ex- 
plained that the said attraction was not so much ex- 
erted upon ocean waters as upon " subterranean spirits 
and humors" — whatever he may have meant by such 
an expression. 

Kepler, not long after Gilbert, made further ad- 
vance. He gained some definite notions as to the na- 
ture of gravity ; and he saw distinctly that the moon's 
attraction was the main cause of the tides. The fol- 
lowing remarkable statement is found in his writings : 
"If the earth ceased to attract its waters, the whole 
sea would mount up and unite itself with the moon. 
The sphere of the attracting force of the moon ex- 
tends even to the earth, and draws the waters towards 
the torrid zone, so that they rise to the point which 
has the moon in the zenith." Here is a distinct enough 
grasp of the fact that gravity can and does act through 
distance, between worlds separated by thousands of 
miles. 

Yet, though both Gilbert and Kepler saw so much, 



ISAAC NEWTON. 389 

they failed to go farther. Neither of the two had any 
clear knowledge of the modes in which gravitation 
acts, or of the laws which govern its working. Gil- 
bert and Kepler alike, while dimly recognizing, not 
only the moon's attraction for earth's oceans, but the 
mutual attraction of earth and moon each for the other, 
were utterly perplexed as to what force could possi- 
bly hold the two bodies asunder. Gilbert could se- 
riously talk of "subterranean spirits and humors." 
Kepler could soberly write of an " animal force" or 
some tantamount power in the moon, which prevented 
her nearer approach to earth. 

Galileo was equally vague on the subject. With all 
his brilliant gifts, and while acknowledging the earth's 
attractive power over the moon, he would not even 
admit the existence of mutual attraction, and talked 
of the moon as being compelled to "follow the»earth." 
Unquestionably there are times when the moon does 
follow the earth, and that is when the earth happens 
to go before. But quite as often it happens that the 
moon goes before, and the earth follows after. 

All these great men were groping near the truth, 
yet none managed to find the clue that was wanted. 
They left the unfinished process of thought to be car- 
ried on by the master-mind of Newton. And Newton 
set himself to think the question out. He used Kep- 
ler's observations. He sought to penetrate the secrets 
of a Solar System in mysterious and inviolable order. 
Some reason or cause for that order he knew must ex- 
ist — if only it might be grasped ! He pondered deeply ; 
lost in profound cogitation, through stormy days of 
civil strife, of plague and loss and suffering. The 



390 STORY OF THE SUN, MOON, AND STARS. 

object of his life was to discover, if so he might, what 
power or what forces retained the different worlds in 
their respective pathways; in short, what manner of 
celestial guidance was vouchsafed to the planets. 

For although men had now learned the shape of the 
planet-orbits, and even knew certain laws which helped 
to govern the planet-motions, they had not discovered 
one supreme controlling law. They did not dream of 
gravity in the heavens as a prevailing force. There 
was absolutely no reason, with which men were ac- 
quainted, why each planet should preserve its own 
particular distance from the sun ; why Mars should not 
wander as far away as Jupiter ; why Mercury should 
not flee to the position of Saturn; why our own 
earth should be always about as near as she al- 
ways is. 

The resources of Newton's genius seemed equal to 
almost any demand that could be made upon it. He 
saw that each planet must disturb the other, and in 
that way he was able to render a satisfactory account 
of certain phenomena which had perplexed all pre- 
ceding investigators. That mysterious movement by 
which the pole of the earth sways about among the 
stars, had been long an unsolved enigma; but New- 
ton showed that the moon grasped with its attraction 
the protuberant mass at the equatorial regions of the 
earth, and thus tilted the earth's axis in a way that 
accounted for the phenomenon which had been known, 
but had never been explained, for two thousand years. 
All these discoveries were brought together in that 
immortal work, Newton's "Principia," the greatest 
work on science that the world had yet seen. 



ISAAC NEWTON. 39 1 

It may well be that, as Newton pondered this per- 
plexing question while seated in the garden, an apple 
dropping to the ground might have sufficed to turn his 
wide-awake and ready mind in the direction of that 
familiar force, gravity, which draws all loose bodies to- 
wards earth's surface. The apple fell because of grav- 
ity. Quite naturally the question might have arisen 
in Newton's mind — " Why not this same gravity in the 
heavens also? If the earth draws an apple towards 
herself, why should not the earth draw the moon? 
Why should not the sun draw the earth ? Nay, more, 
why should not the sun draw all the planets?'' Newton 
set himself to work out this problem, allowing for the 
distance of the moon from earth, and for the bulk and 
weight of both earth and moon. 

And because the answer was not precisely what he 
had looked for, he put the calculation aside, and 
waited for years. It seems that he mentioned his con- 
jecture to no living person. After many years he took 
it up again, and worked it out afresh. By this time 
new measurements of earth's surface, and new calcu- 
lations of earth's size had been made, and Newton had 
fresh figures to go upon. This time the answer came 
just as he had originally hoped, and the truth of his 
surmise was thus proved. 

Gravity held the moon near the earth, preventing 
her from wandering off into unknown distances. Grav- 
ity held earth and moon, Mars, Venus, Jupiter, each 
planet, in its own pathway, within a certain distance 
of the sun. Gravity held many of the comets as per- 
manent members of the Solar System. So strong, 
indeed, was the drawing of gravity found to be, that 



392 STORY OF THE SUN, MOON, AND STARS. 

only the resisting force of each bright world's rapid 
rush round the sun could keep the sun and his plan- 
ets apart. 

Newton had discoved the long-sought secret. He 
had found that " every particle of matter in the uni- 
verse attracts every other particle." He had found 
also the main laws which govern the working of that 
attraction — that it depends, first, upon the mass or 
amount of " matter" in each body; that it depends, 
secondly, upon the distance of one body from another. 
He found, too, how far attraction increases with greater 
nearness, and decreases with greater distance. All 
these and countless other questions he worked out in 
the course of years. But first he had grasped the 
great leading principle, after which men had until then 
groped in vain, that by the force of gravity the sun 
and his worlds and their moons are all bound together 
into one large united family or system. 

Though Newton lived long enough to receive the 
honor that his astonishing discoveries so justly mer- 
ited, and though for many years of his life his renown 
was much greater than that of any of his contempo- 
raries, yet it is not too much to say that, in the years 
which have since elapsed, Newton's fame has been 
ever steadily advancing. 

We hardly know whether to admire more the sub- 
lime discoveries at which he arrived, or the extraor- 
dinary character of the intellectual processes by which 
those discoveries were reached. He died on Monday, 
March 20, 1727, in the eighty-fifth year of his age. 



CHAPTER XXXV. 

LATER ASTRONOMY. 

Sir William Herschel was born in the city of 
Hanover, November 15, 1738. He was the second 
son of Isaac Herschel, a musician, who brought him 
up, with his four other sons, to his own profession. 

A faithful chronicler has given us an interesting ac- 
count of the way in which Isaac Herschel educated 
his boys; the narrative is taken from the recollections 
of one who, at the time, was a little girl of five or six 
years old. She writes : 

"My brothers were often introduced as solo per- 
formers and assistants in the orchestra at the court, 
and I remember that I was frequently prevented from 
going to sleep by the lively criticisms on music on 
coming from a concert. Often I would keep myself 
awake that I might listen to their animated remarks, 
for it made me happy to see them so happy. But 
generally their conversation would branch out on 
philosophical subjects, when my brother William and 
my father often argued with such warmth that my 
mother's interference became necessary when the 
names Euler, Leibnitz, and Newton sounded rather 
too loud for the repose of her little ones, who had to 
be at school by seven in the morning. " 

The child, whose reminisences are here given, be- 
came afterwards the famous Caroline Herschel. The 
narrative of her life is a most interesting book, not 

393 



394 STORY OF THE SUN, MOON, AND STARS. 

only for the account it contains of the remarkable 
woman herself, but also because it presents the best 
picture we have of the great astronomer, to whom 
Caroline devoted her life. 

This modest family circle was, in a measure, dis- 
persed at the outbreak of the Seven Years* War in 
1756. The French proceeded to invade Hanover, 
which, it will be remembered, belonged at this time 
to the British dominions. Young William Herschel 
had already obtained the position of a regular per- 
former in the regimental band of the Hanoverian 
Guards, and it was his fortune to obtain some experi- 
ence of actual warfare in the disastrous battle of 
Hastenbeck. He was not wounded, but he had to 
spend the night after the battle in a ditch, and his 
meditations on the occasion convinced him that sol- 
diering was not the profession exactly suited to his 
tastes. He left his regiment by the very simple, but 
somewhat risky, process of desertion. He had, it 
would seem, to adopt disguises in order to effect his 
escape. By some means he succeeded in eluding de- 
tection, and reached England in safety. 

The young musician must have had some difficulty 
in providing for his maintenance during the first few 
years of his abode in England. 

It was not until he had reached the age of twenty- 
two that he succeeded in obtaining any regular appoint- 
ment. He was then made instructor of music to the 
Durham Militia. Shortly afterwards, his talents being 
more widely recognized, he was appointed as organist 
of the parish Church at Halifax. 

In 1766 we find that Herschel had received the 



X.ATKR ASTRONOMY. 395 

further promotion of organist in the Octagon Chapel, 
at Bath. Bath was then, as now, a highly fashionable 
resort, and many notable personages patronized the 
rising musician. Herschel had other points in his 
favor besides his professional skill ; his appearance was 
striking, his address superb, and his conversation an- 
imated, interesting, and instructive; and even his na- 
tionality was a distinct advantage, inasmuch as he 
was a Hanoverian in the reign of King George the 
Third. From h. s earliest youth, Herschel had been en- 
dowed with thai invaluable characteristic, an intense 
desire for knowledge. He naturally wished to per- 
fect himself in the the Dry of music, and thus he was 
led to study mathematics. When he had once tasted 
the charms of mathematics, he saw vast regions of 
knowledge unfolded before him, and in this way he 
was induced to direct his attention to astronomy. 
More and more this pursuit engrossed his attention 
until, at last, it had become an absorbing passion. 

It was with quite a small telescope, which had been 
lent him by a friend, that Herschel commenced his 
career as an observer. However, he speedily discov- 
ered that to see all he wanted to see, a telescope of 
far greater power would be necessary. 

He commissioned a friend to procure for him in 
Ivondon a telescope with high magnifying power. 
Fortunately for science the price was so great that it 
precluded the purchase, and he set himself at work to 
construct one. After many trials he succeeded in mak- 
ing a reflecting instrument of five feet focal length, 
with which he was able to observe the rings of Sat- 
urn and the satellites of Jupiter. 



396 STORY OF THE SUN, MOON, AND STARS. 

It was in 1774, when the astronomer was thirty- 
six years old, that he obtained his first glimpse of the 
stars with an instrument of his own construction. 
Night after night, as soon as his musical labors were 
ended, his telescopes were brought out. 

His sister Caroline, who occupies such a distinct 
place in scientific history, the same little girl to whom 
we have already referred, was his able assistant, 
and when mathematical work had to be done, she 
was ready for it. She had taught herself sufficiently 
to enable her to perform the kind of calculations — -not, 
perhaps, very difficult ones — that Herschel' s work re- 
quired ; indeed, it is not much to say that the mighty 
life-work which this man was enabled to perform 
could never have been accomplished had it not been for 
the self-sacrifice of this ever-loving and faithful sister. 

It was not until 1782 that the great achievement 
took place by which Herschel at once sprang into 
fame. He appears to have formed a project for mak- 
ing a close examination of all the stars above a cer- 
tain magnitude for the purpose of discovering, if possi- 
ble, a parallax among them. Star after star was brought 
to the center of the field of view of his telescope, and 
after being carefully examined, was then displaced, 
while another star was brought forward to be sub- 
mitted to the same process. 

In the great review which Herschel undertook, he 
doubtless examined hundreds, or perhaps thousands of 
stars, allowing them to pass away without note or com- 
ment. But on an ever-memorable night in March, 1782, 
it happened that he was pursuing his task among the 
stars in the constellation of Gemini. One star was 



LATER ASTRONOMY. 397 

noticed which, to Herschel's acute vision, seemed dif- 
ferent from the stars which in so many thousands are 
strewn over the sky. There was something in the 
starlike object that immediately arrested his attention, 
and made him apply to it a higher magnifying power. 
This at once disclosed the fact that the object pos- 
sessed a disk — that is, a definite, measurable size — and 
that it was thus totally different from any of the hun- 
dreds and thousands of stars which exist elsewhere in 
space. The organist at the Octagon Chapel at Bath 
had discovered a new planet with his home-made 
telescope. Great was the astonishment of the scien- 
tific world when the Bath organist announced that the 
five planets, which had been known from all antiquity, 
must now admit the company of a sixth. 

The now great astronomer was invited to Windsor, 
and to bring his famous telescope in order to exhibit 
the planet to George III, and to tell his majesty all 
about it. The king took so great a fancy to Herschel 
that he proposed to confer on him the title of "his 
majesty's own astronomer,'* to assign him a residence 
near Windsor, to provide him with a salary, and to 
furnish such funds as might be required for the erec- 
tion of great telescopes, and for the conduct of that 
mighty scheme of celestial observation on which Her- 
schel was so eager to enter. 

No single discovery of HerschePs later years was, 
however, of the same momentous description as that 
which first brought him to fame. There is no sepa- 
rate collection of his writings, and very scanty accounts 
of his life have been published ; but he who has 
written his name among the stars needs no other 



398 STORY OF THE SUN, MOON, AND STARS. 

testimonial to his fame. Prior to his time the num- 
ber of bodies known as belonging to the Solar Sys- 
tem was eighteen, including secondary planets and 
Halley's comet. To these he added nine ; namely, 
Uranus and six satellites, and two satellites of Saturn. 
Though no additional honors could add to his fame, 
Dr. Herschel, in 1816, received the decoration of the 
Guelphic Order of Knighthood. In 1820 he was elected 
president of the Astronomical Society, and among their 
Transactions, the next year, he published an interest- 
ing memoir on the places of one hundred and forty- 
five double-stars. This paper was the last which he 
lived to publish. His health had begun to decline, 
and on the 24th of August, 1822, he sank under the 
infirmities of age, having completed his eighty-fourth 
year. He was survived by his widow, Lady Herschel, 
an only son, Sir John F. W. Herschel, and his sister 
Caroline, who died in 1847, in her ninety-eighth year. 

Laplace. 

The author of "Celestial Mechanics " was born at 
Beaumont-en- Auge in 1749, just thirteen years later 
than his renowned friend Lagrange. His father was 
a farmer, but appears to have been in a position to 
provide a good education for a son who seemed prom- 
ising. The subject which first claimed his attention 
was theology. He was, however, soon introduced to 
the study of mathematics, in which he presently be- 
came so proficient that, while he was still no more 
than eighteen years old, he obtained employment as a 
mathematical teacher in his native town. 

Desiring wider opportunities for study, young La- 



LATER ASTRONOMY. 399 

place started for Paris, being provided with letters of 
introduction to D'Alembert, who then occupied the 
most prominent positions as a mathematician in 
France, if not in Europe. On presenting these let- 
ters, he seems to have had no reply; whereupon, La- 
place wrote to D'Alembert, submitting a discussion of 
some point in dynamics. 

This letter instantly produced the desired effect. 
D'Alembert thought that such mathematical talent as 
the young man displayed was in itself the best of in- 
troductions to his favor. It could not be overlooked, 
and accordingly he invited Laplace to come and see 
him. Laplace, of course, presented himself, and ere- 
long D'Alembert obtained for the rising philosopher 
a professorship of Mathematics in the military school 
in Paris. This gave the brilliant young mathema- 
tician the opening for which he sought, and he quickly 
availed himself of it. 

Laplace's most famous work is "Celestial Mechan- 
ics, " in which he essayed a comprehensive attempt to 
carry out, in much greater detail, the principles which 
Newton had laid down. The fact was that Newton 
had not only to construct the theory of gravitation, 
but he had to invent the mathematical processes by 
which his theory could be applied to the explanation 
of the movements of the heavenly bodies. In the 
course of the century which had elapsed between the 
time of Newton and the time of Laplace, mathemat- 
ics had been extensively developed. The disturbances 
which one planet exercises upon the rest can only be 
fully ascertained by the aid of long calculations, and 
for these calculations analytical methods are required. 



4-00 STORY OF THE SUN, MOON, AND STARS. 

With an armament of mathematical methods 
which had been perfected since the days of New- 
ton by the labors of two or three generations of math- 
ematical inventors, Laplace essayed in his " Celestial 
Mechanics " to unravel the mysteries of the heavens. 
It will hardly be disputed that the book which he has 
produced is one of the most difficult books to under- 
stand that has ever been written. The investigations 
of Laplace are, generally speaking, of too technical a 
character to make it possible to set forth any account 
of them in such a work as the present. He did, how- 
ever, publish one treatise, called the "System of the 
Universe," in which, without introducing mathematical 
symbols, he was able to give a general account of the 
theories of the celestial movements, and of the discov- 
eries to which he and others had been led. In this 
work Laplace laid down the principles of the nebu- 
lar theory, which, in modern days, has been generally 
accepted. 

The nebular theory gives a physical account of the 
origin of the Solar System, and has already been ex- 
plained in this volume. Bach advance in science 
seems to make it more certain that this hypothesis 
substantially represents the way in which our Solar 
System has grown to its present form. 

Not satisfied with a career which was merely sci- 
entific, Laplace sought to connect himself with public 
affairs. Napoleon appreciated his genius, and desired 
to enlist him in the service of the state. Laplace was 
appointed to the office of minister of the interior. The 
experiment was not successful, for he was not by na- 
ture a statesman. In despair of Laplace's capacity as 



LATER ASTRONOMY. 4OI 

an administrator, Napoleon declared that he carried 
the spirit of his infinitesimal calculus into the man- 
agement of business. Indeed, Laplace's political con- 
duct hardly admits of much defense. While he ac- 
cepted the honors which Napoleon showered on him 
in the time of his prosperity, he seems to have forgot- 
ten all this when Napoleon could no longer render him 
service. Laplace was made a marquis by Louis XVIII. 
During the latter part of his life the philosopher lived 
in a retired country-place at Arcueile. Here he pur- 
sued his studies, and, by strict abstemiousness, pre- 
served himself from many of the infirmities of old age. 
He was endowed with remarkable scientific sagac- 
ity; but above all his powers his wonderful memory 
shone pre-eminent. His "Celestial Mechanics " is, 
next to Newton's " Principia," the greatest of astro- 
nomical works. 

He died on March 5, 1827, in his seventy-eighth 
year, his last words being, "What we know is but lit- 
tle, what we do not know is immense." 

Leverrier. 
We are apt to identify the idea of an astronomer 
with that of a man who looks through a telescope at 
the stars ; but the word astronomer has really a much 
wider significance. No man who ever lived has been 
more entitled to be designated an astronomer than 
Urbain Jean Joseph Leverrier, and yet it is certain 
that he never made a telescopic discovery of any kind. 
In mathematics, however, he excelled, and he simply 
used the observations of others as the basis of his cal- 
culations. 



402 STORY OF THK SUN, MOON, AND STARS. 

These observations form, as it were, the raw mate- 
rial on which the mathematician exercises his skill. 
It is for him to elicit from the observed places the 
true laws which govern the movements of the heav- 
enly bodies. Here is indeed a task in which the 
highest powers of the human intellect may be worth- 
ily employed. To Leverrier it has been given to pro- 
vide a superb illustration of the success with which 
the mind of man can penetrate the deep things of 
nature. 

The illustrious Frenchman was born on the nth of 
March, 181 1, at Saint-L6, in the department of Manche. 
In the famous polytechnic school for education in the 
higher branches of science he acquired considerable 
fame as a mathematician. His labors at school had 
revealed to Leverrier that he was endowed with the 
powers requisite for dealing with the subtlest instru- 
ments of mathematical analysis. When he was 
twenty-eight years old his first great astronomical in- 
vestigation was brought forth. This was the pro- 
found calculation of the disturbances of the planet 
Uranus and the causes of them. 

The talent which his researches displayed brought 
Leverrier into notice. At that time the Paris Ob- 
servatory was presided over by Arago, a savant who 
occupies a distinguished position in French scientific 
annals. Arago at once perceived that Leverrier pos- 
sessed the qualifications suitable for undertaking a 
problem of great importance and difficulty that had 
begun to force itself on the attention of astronomers. 
What this great problem was, and how astonishing was 
the solution it received, must now be considered. 



LATER ASTRONOMY. 403 

Ever since Herschel brought himself into fame by 
the discovery of Uranus, the movements of this new 
addition to the Solar System had been scrutinized 
with care and attention. The position of Uranus was 
thus accurately determined from time to time. When 
due allowance was made for whatever influence the 
attraction of Jupiter and Saturn and all the other plan- 
ets could possibly produce, the movements of Uranus 
were still inexplicable. It was perfectly obvious that 
there must be some other influence at work besides 
that which could be attributed to the planets already 
known. 

Astronomers could only recognize one solution of 
such a difficulty. It was impossible to doubt that 
there must be some other planet in addition to the 
bodies at that time known, and that the perturbations 
of Uranus, hitherto unaccounted for, were due to the 
disturbances caused by the action of this unknown 
planet. Arago urged Leverrier to undertake the great 
problem of searching for this body. But the condi- 
tions of the search were such that it must be con- 
ducted on principles wholly different from any search 
which had ever before been undertaken for a celestial 
object. For this was not a case in which mere survey 
with a telescope might be expected to lead to the dis- 
covery. 

There are in the heavens many millions of stars, 
and the problem of identifying the planet, if indeed it 
should lie among these stars, seemed a very complex 
matter. Of course, it is the abundant presence of the 
stars which causes the difficulty. 

The materials available to the mathematician for 



404 STORY OF THE SUN, MOON, AND STARS. 

the solution of this problem were to be derived solely 
from the discrepancies between the calculated places 
in which Uranus should be found, taking into account 
the known causes of disturbances, and the actual 
places in which observation had shown the planet to 
exist. Here was, indeed, an unprecedented problem, 
and one of extraordinary difficulty. Leverrier, how- 
ever, faced it, and, to the astonishment of the world, 
succeeded in carrying it through to a brilliant so- 
lution. 

After many trials, Leverrier ascertained that, by 
assuming a certain size, shape, and position for the 
unknown planet's orbit, and a certain value for the 
mass of the hypothetical body, it would be possible to 
account for the observed disturbances of Uranus. 
Gradually it became clear to his perception, not only 
that the difficulties in the movements of Uranus 
could be thus explained, but that no other explana- 
tion need be sought for. And now for an episode in 
this history which will be celebrated so long as sci- 
ence shall endure. It is nothing less than the tele- 
scopic confirmation of the existence of this new planet, 
which had previously been indicated only by mathe- 
matical calculation. 

Great indeed was the admiration of the scientific 
world at this superb triumph. Here was a mighty 
planet, whose very existence was revealed by the indi- 
cations afforded by refined mathematical calculation. 
At once the name of Leverrier, already known to 
those conversant with the more profound branches of 
astronomy, became everywhere celebrated. 

When, in 1854, Arago's place had to be filled at 



LATER ASTRONOMY. 405 

the head of the great Paris Observatory, it was uni- 
versally felt that the discoverer of Neptune was the 
suitable man to assume the office. Leverrier died on 
Sunday, September 23, 1877, in his sixty-seventh year. 

Frederick William Bessel was born at Minden 
in 1784, and early turned his attention to mathematical 
subjects. He devoted himself with ardor to astron- 
omy, and in 1804 he undertook the reduction of the 
observations made on the comet of 1607. His results 
were communicated to Olbers, who warmly praised 
the young astronomer, and in 1806 recommended him 
to Schroeter as an assistant in the observatory of Lil- 
ienthal. In 1810 he was appointed director of the 
new observatory then being founded by the king at 
Konigsberg. He was admirably fitted for this post, 
and is distinguished mainly for his discovery of the 
parallax of the star 61 Cygni, which he accomplished 
by methods of extreme ingenuity and delicacy. 

Two kinds of telescopes are commonly used, the 
refractor and the reflector. The first telescopes made 
were all refractors, and the very first of them was 
made, as you know, by Galileo. The first reflector 
was made in later days by Sir Isaac Newton. 

In a refractor the rays of light, from a star or any 
other bright body, reach first a large object-glass, 
through which they pass, and by which, as they pass, 
they are caused to converge, narrowing to a focus or 
point. From this point they widen slightly on their 
way to the eye-piece. After passing through the eye- 
piece, by which they are once more straightened into 
parallel rays, they arrive at the eye. 



406 STORY OF THE SUN, MOON, AND STARS. 

Speaking broadly, the eye receives — actually sees — 
nearly as much of the starlight as if its pupil were 
the full size of the object-glass of that telescope, and 
the power of such an instrument depends upon the 
size of the object-glass. A refractor has been made 
with an object-glass forty inches across, and this, for 
the observer, means looking at a star with an eye- 
pupil more than three feet in diameter. This refractor 
is now in the Yerkes Observatory at Williams Bay, 
Lake Geneva, Wisconsin. 

There are several forms of reflectors. With one 
form, when it is pointed at a star, the rays of starlight 
fall direct through the telescope-tube upon a highly- 
polished mirror, so shaped that rays of light reflected 
thence are caused to fall converging upon a small 
plane-mirror in the center of the tube, from which 
they are thrown, parallel to the side of the tube, to the 
eye-piece, which converges them to the eye. 

The mirror of a reflector can be made very much 
larger than the object-glass of a refractor. The fa- 
mous Lord Rosse telescope, which has a tube sixty 
feet long, contains a mirror no less than six feet in 
diameter. This, to an observer, is tantamount to 
looking at the stars with an eye so huge that its pupil 
alone would be nearly equal in size to the six-foot 
wheel of a steam-engine. It will readily be perceived 
how much more starlight can be grasped by such a 
fishing-net than by the tiny pupil of your eye or 
mine. 

A main difference between the two kinds of tele- 
scope thus resides in the fact that the star-rays — or 
any other kind of light-rays — when first captured, 



I^ATER ASTRONOMY. 



407 



pass, in one case, through the glass on which they 
fall, and, in the other case, are thrown off from the 
mirror. In both cases, the whole amount of light so 




S^S^sS 



eye-piece; of the uck telescope. 



captured is gathered into a small compass, so as to be 
available for human sight. 

Once more, let me remind you, it should be always 
kept clearly in mind that every object that is seen by 



408 STORY OF THE SUN, MOON, AND STARS. 

us — from a mote of dust to a sun, from a coal-scuttle 
to a star — is perceived purely and solely by the light 
which it gives out, either intrinsic or reflected light. 
Countless myriads of rays pass from the surface of the 
thing seen to our eyes, picturing there, on the sensi- 
tive retina, a fleeting vision of its form. 

All the leading Governments in Europe have ob- 
servatories for the study of the heavens, which are 
furnished with the best instruments of modern con- 
struction. The principal obseivatories are those at 
Paris, Berlin, Vienna, Nice; Dorpat, the seat of a cele- 
brated university founded by Gustavus Adolphus, of 
Sweden, in 1630; Pulkowa, near St. Petersburg; Lis- 
bon, and at Greenwich in England. In America, 
though only in recent years has astronomy been culti- 
vated with ardor, there are observatories of more or 
less importance, — the National Observatory at Wash- 
ington, D. C. ; the Cincinnati Observatory, projected 
by the late General O. M. Mitchel; the Dudley Ob- 
servatory, founded by Mrs. Blandina Dudley in honor 
of her husband, at Albany, N. Y. ; the Lick Observa- 
tory, founded by James Lick, on Mount Hamilton, Cal. ; 
and the Yerkes Observatory, connected with the Chi- 
cago University, founded by Charles T. Yerkes. Be- 
sides these, there are observatories connected with some 
of our other leading universities and colleges, as those 
of Harvard, at Cambridge, Mass.; Yale University; 
Williams College ; West Point Military Academy ; Am- 
herst College ; Princeton; Dartmouth; Michigan Uni- 
versity ; Hamilton College, N. Y., and several others. 

The largest and best refracting telescopes in the 
world are those at Lick Observatory and at Yerkes 




409 



410 STORY OF THE SUN, MOON, AND STARS. 

Observatory, now in charge of Professor E. E. Barnard, 
who, while at the head of the Lick Observatory, dis- 
covered the fifth satellite of Jupiter, and determined 
the character of the inner ring of Saturn. The best 




E. E. BARNARD. 

reflecting telescope is that of Lord Rosse, at Birr Cas- 
tle, in Kings County, Ireland. 

In reviewing the path which we have traversed in 
this volume, though we have penetrated the sidereal 
depths and wandered at will through space, we feel 



LATER ASTRONOMY. 41 1 

that we have not yet reached the outskirts of creation. 
We have never left the center. Beyond ns still lies 
the circumference. We see opened before us the in- 
finite, of which the study is not yet begun ! We have 
seen nothing ; we recoil in terror ; we fall back as- 
tounded. Indeed, we might fall into the yawning 
abyss — fall forever, during a whole eternity; never, 
never should we reach the bottom, any more than we 
have attained the summit. There is no east nor west, 
neither right nor left. There is no up nor down; 
there is neither a zenith nor a nadir. In whatever 
way we look, it is infinite in all directions. 

In this infinitude of space, the associations of suns 
and of worlds which constitute our visible universe form 
but an island, a vast archipelago ; and in the eternity 
of duration, the life of our proud humanity, with all 
its concerns, its aspirations, and its achievements, the 
whole life of our entire planet, is but the shadow of a 
dream ! Well might the Hebrew poet, as he looked 
forth upon nature, exclaim in his amazement: " When 
I consider thy heavens, the work of thy fingers, the 
moon and the stars which thou hast ordained, what is 
man that thou art mindful of him, and the son of man 
that thou visitest him?" 

The constellations, the charts of the sky; the cata- 
logues of curious stars — variable, double or multiple, 
and colored; the description of instruments accessible 
to the observer of the heavens, and useful tables to 
consult, are only touched upon in this volume. The 
reader whose scientific desires are satisfied by the ele- 
ments of astronomy, may stop here. Few have time 
to pursue the subject further; but it is sweet to live 



412 STORY OF THK SUN, MOON, AND STARS. 

in the sphere of the mind ; it is sweet to contemn the 
rough noises of a vulgar world ; it is sweet to soar in 
the ethereal heights, and to devote the best moments 
of our life to the study of the true, the infinite, and 
the eternal! 



PUBLISHERS' NOTE. 

Wk have now reached the conclusion of "The 
Story of the Sun, Moon, and Stars." Miss Giberne's 
work has been supplemented with a large amount of 
matter from other sources. The value of the book 
has thus been increased without diminishing its pop- 
ular character. In most admirable form it tells the 
story of the heavenly world, which is the work of 
God's hands, the moon and the stars which he has 
made. The reverent reader, to whom the Word of 
God is " sweeter than honey and the honey-comb," 
may here find that " the heavens declare the glory of 
God, and the firmament showeth his handiwork." 
We confidently present it to the reader as the best 
and completest work in print on the great subject of 
which it treats. 



INDEX. 



PAGE. 

Adams, John Couch, 231,236 

Aerolites, 84 

Size of, 86 

Aldebaran, Movement of, 277 

Alexander at Arbela, 146 

Alpha Centauri, Distance of, . . . 99 

Duration of light journey, . . . 102 

Position, 279 

Alps, I,unar Mountains, 179 

Altai, I,unar Mountains, 179 

Andromeda, Constellation of, . . 112 
Apennines, Lunar Mountains, . . 179 

Arago, 235, 402 

Arcturus, Motion of, 114 

Position, 276 

Aristotle 376 

Asteroids, 53 

Astronomy, The dawn of, .... 363 

Attraction, 34 

Aurora Borealis, where seen, ... 141 
Axis of earth slanting, 44 

Barnard, K. K., 53, 410 

Bessel, F. W., 284 

Discovery of star parallax, . . . 324 
Discovers star parallax, .... 405 

Bolides, 87, 257 

Borelli, 388 

Capella, Duration of light 

journey , 103 

Velocity of motion, ....... 114 

Caucasian Range, Lunar Moun- 
tains 179 

Carpathian, Lunar Mountains, . . 179 

Carrington, 141 

Cassini, Measurement of sun's 

distance 310 

Cassiopeia, Constellation of, . . . 112 

Ceres, size of, 53 

Chaldean star-gazers 365 

Chinese records of eclipses, . . . 365 



page. 
Cicero, 177 

Clark, Alvan Graham, 289 

Cloven-disk theory, 331 

Coal sack, 329 

Columbus in Jamaica 146 

Comet, Biela's, 90, 93 

Halley's, 78, 248 

Of 1843, 80 

Newton's 78 

With two tails, 77 

Encke's, 78 

Heat endured by, 81 

Length of tail, 81 

Collision with, 82 

Split in two, 91 

Comets, 73, 240, 246 

Number of, 75 

Nature of, 74 

Captured by Jupiter, 213 

Composition of, 256 

Composition of tails, 253 

Orbits of, 129 

With closed orbits, 76 

Confucius as an astronomer, . . . 365 
Constellations, Grouping, .... 366 

When named, 366 

Copernicus, Author of" Celestial 
Spheres," . . . 177, 183, 370, 371, 375 

Star parallax, 319 

Copernican system of the uni- 
verse, 175 

Corona, Description of, 153 

D'Alembert, 399 

Dante, 121 

Demos, Satellite of Mars, .... 191 

Donati's Comet, 248, 250 

Draco, Constellation of, 112 

Earth, Globular 17 

How formed 21 

Member of the Solar System, . . 14 



413 



4 i4 



INDEX. 



Earth, Globular— page. 

In motion,. , 16 

Motions, 18, 41, 126 

One of a family, 14 

Size of, 26 

What is it ? 13 

Ecliptic, 43 

Eclipses omens of evil, 145 

Egyptian astronomers, 365 

Encke 238 

Epicycles, .... 373 

Equinox, 44 

Eire-balls, Speed of, 88 

Fabrcius discovers sun-spots, . . 27 
Fraunhofer, Joseph von, ..... 345 

Galle, 232, 238 

Galileo, . . . .28,276,371,376,378,380 

Gassendi, 184 

George III, 226 

Gilbert, 388 

Great Bear, Constellation of, . 108, 340 

Halley, 388 

Transit of Venus, 314 

Star motions, 318 

Hercules, Constellation of, ... . 112 

Herschel, Caroline, 226, 393 

Herschel, Sir John, . . 81, 233, 303, 398 
Herschel, William, . 96, 119, 225, 271, 393 

Hipparchus, 368, 371 

Hodgson, 141 

Holland, Sir Henry, 237 

Hook, Robert, 388 

Horrocks, 388 

Huggins, Dr 359 

Humboldt, Alexander von, .... 265 

Jupiter 55 

Comparative size, 56 

Distance of, 122 

His satellites, 56, 206, 210 

Velocity, . 199 

Wind storms, 204 

Kepler, 75, 296 

Laws of, 371, 374, 380, 388 

Kew Observatory 141 



PAGE. 

Lacaille, Catalogue of, .... 105 

Lalande, Catalogue of, 105 

Laplace, 385, 398 

Later astronomy, 393 

Leverrier, Urbain J. J., . . . 231,401 

Discovers Neptune, 321 

Light, Rapidity of, 101 

Time, Duration of, 331 

Lowe at Santander, 147 

Lunar craters, Antiquity of, . . . 172 

How formed, 173 

Plato and Copernicus, 173 

Ptolemy, 174 

Schickard, .... 174 

Tycho 174 

Lunar Mountains, How formed, . 174 
Lyra, Constellation, 297 

Magellanic clouds 309 

Magnetism, 140, 141 

Mars > 52, 373, 374 

Moons of, 191 

Continents of, 197 

Distance from earth, 197 

Maury, Lieutenant, 80 

Mercury, Atmosphere, 181 

Distance from sun, 49 

Length of year, 180 

Is it inhabited? 181 

Orbit of, 180 

Phases, 50 

Size of, 49 

Transit of, 184 

Meteor, 84, 257 

Meteorites, .... 240, 257 

Around the sun, 94 

August system, 90, 242 

In Saturn's rings, . . 94 

November system, ... 90, 94, 241 

Number of, 86 

Protection from, 86 

Shower of 1872, 92 

Shower of 1885 • 93 

Milky Way, .... 270, 329 

Mizar, 342 

Modern Astronomy, 375 

Moon, 62 

Appearance at its full 63 

Atmosphere, 157, 169 

Phases of, 160 



INDEX. 



415 



Moon— page. 

Condition of, 65 

Craters, 68, 170 

Earth's satellite 164 

Earth-shine, 160 

Eclipse, 163 

Influence on tides, 167 

Landscape of, 68 

Mountains, 67 

Orbit of, 166 

Temperature on, 72 

Revolution, 64 

Size of, 64 

Surface 67 

Nasmyth, 173 

Nebulae, Number of, 336 

Neptune, 59 

Discovery of, 232, 234 

Distance of, . 123 

Length of year, 59 

Newton analyzes light, 385 

Birth and childhood, 382 

Nicetos of Syracuse, 177 

Nicias, Athenian General, .... 146 
Nicolas, Cardinal, 177 

Observatories, 408 

Orbits, Planetary, 47 

Orion, Constellation of, 112 

Parallax, 311 

Phobos, Satellite of Mars, .... 191 

Photography, Stellar, 355 

Pius IX, 93 

Pisa, Leaning Tower of, 378 

Plane of tie Ecliptic, 201 

Planets, Durance from the sun, . 123 

First group 48 

How formed, 22 

Length of years, 49 

Orbits, 47 

Order of ioi iiation, 23 

Second group, 48, 55 

Plutarch, . 177 

Pole star, Da- avion of light jour- 
ney, 103 

Position . 108 

Rate of n: j 1 :- , 115 

Prism, . . 344 

Pritcharc, v_ 356 



PAGE 

Ptolemaic system of the universe, 

175, 369 

Ptolemy, 371, 369 

Pythagoras, Grecian astronomer, 367 

Rosse, Lord, Telescope 406 

Rowton siderite, ......... 258 

Saturn, 57 

Composition of rings, 221 

Distance of, ...... • .... 122 

Distance from sun, 214 

Length of year, 57 

Moons, 217 

Rings, 219 

Satellites, 58 

Size, . . 214 

Weight, 214 

Shickard, Crater on the moon, . . 174 

Scheiner, 28 

Secchi 92 

Shooting stars, 84 

Sirius, Brightness of, 275, 285 

Changing color, 285 

Distance of, 100 

Duration of light journey, . . .103 

Movement of, 277 

Solar cloud, 148 

Solar System, 60, 122 

Model of, 60 

Spectroscope, 143, 345 

Spectroscopic photography, . . . 360 

Spectrum analysis, 346, 354 

Star clusters, 304, 336 

Parallax, 284, 316 

Spectroscopy, 356 

Stars, Apparent motion, 107 

Attraction, . 21 

Distance of, 99, 310, 320 

Distance 281, 282 

Fixed, "Why so called 20 

Fixed, Why, 366 

Golden, 274 

Magnitude of, . . . • 97 

How many visible, 95 

Measurement, 278 

Red, ... 274 

Variable 274, 291 

White, 274 

Sun, 24 

Attraction of, 156 



4 i6 f 



INDEX. 



Sun — PAGE. 

Attraction of gravitation, ... 34 

Chromatosphere, 32 

Cyclones of, 30, 136 

Density, 26 

Destination, .119 

Distance of, 25 

Eclipse of, 143 

Flames, Their height, ... 31, 151 

Flames, Their velocity, 138 

Forces and influences, 39 

Head of our family, . . 24 

Magnetic power of, 139 

Its mottled appearance, .... 142 

Rate of motion, 119 

Penumbra 133 

Photosphere, 31, 134 

Power of, 39, 137 

Rapidity of motion, 26 

Revolution on axis, 28 

Size, 26, 154 

Solar prominence, 32 

Spots 27, 30, 133 

Symbol of purity, 380 

Umbra, 133 

Weight, 27, 154 

Swift, Voyage to Taputa, 194 

Telescopes 378, 379, 405 

Refractors and reflectors, 405, 

408, 410 



PAGE. 

Tides, 168 

Thales, founder of Grecian As- 
tronomy, 367 

Toucan, 306 

Tycho Brahe, 175, 371, 372, 373 

Universe, Definition of, .... 19 

Uranus, 58 

Discovery of, 225 

Distance of, 123 

Venus, Orbit of 51 

Is it inhabited? 189 

Distance from earth, 186 

Phases of, 51, 379 

Transits of, 185 

Vesta, Size of, 53 

Voltaire, Prophecy of, 193 

Wilson, 30 

Wollastou, Dr. W. H., ...... . 345 

Wren, 388 

Yerkes Observatory, ...... 406 

Young, Chas. A., 142,148 



Zodiacal Light, 



94, 224, 265 



J Ml 



mm 



